The present invention relates to a spinning rotor for an open-end spinning device, comprising a rotor shaft, via which the spinning rotor is driven with the aid of a belt, in particular, a tangential belt. The rotor shaft includes a contact area for the belt.
With respect to spinning rotors of open-end spinning machines, it has been common for a long time to drive these spinning rotors with the aid of a tangential belt which rests against the shaft of the spinning rotor. The spinning rotors are usually mounted on support disks in this case. The belt is generally pressed against the rotor shaft in this case with the aid of an additional drive roller in order to reduce the slip between the belt and the rotor shaft. In this case, it can also be provided to change the contact pressure of the pressure roller in order, for example, to provide for a faster ramp-up of the spinning rotors or to enable an adaptation to different spinning materials or the like. Such an open-end spinning device comprising a pressure roller onto which a different contact pressure can be applied is described, for example, in DE 101 07 254 A1. Due to the slip between the belt and the rotor shaft, wear can occur on the belt as well as the spinning rotor, however, despite the pressure roller.
In order to reduce the wear of the rotor shaft of the open-end spinning rotor, it has already been proposed to provide the rotor shaft with a wear-reducing coating in the contact area of the tangential belt. Due to a wear of the belt, however, there may nevertheless be an insufficient force transmission between the belt and the rotor shaft, and so the spinning rotors can only be accelerated very slowly or may never even reach their operating speed. If the contact pressure of the pressure roller is increased in this case, this force not only acts on the tangential belt and the rotor shaft, but the rotor shaft is also simultaneously pressed more strongly into the wedge gap of the support disks. This results in increased flexing work in the lining of the support disks, which results in considerable energy consumption in the area of the rotor bearing. This has a negative effect, in particular, in the case of the present-day spinning machines comprising increasingly faster running open-end spinning rotors having rotational speeds of 170,000 1/min and higher.
A problem addressed by the present invention is therefore that of providing a spinning rotor and an open-end spinning device which can be operated with lower energy consumption. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The problems are solved with the aid of a spinning rotor with the features described and claimed herein.
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, in particular, a tangential belt. The rotor shaft includes a contact area for the belt in this case. It is now provided that the contact area of the spinning rotor is provided with a friction coefficient-increasing lining made of an elastomeric material. The term “friction coefficient-increasing” is understood to mean, in this case, an increase in the friction coefficient with respect to the base material and/or the surface material of the shaft. An “elastomeric material” is understood, within the scope of the present invention, to be an elastically deformable material based on plastic or rubber. A material is elastically deformable when it has a modulus of elasticity of less than 1000 MPa.
If the spinning rotor is provided with the friction coefficient-increasing lining in the contact area of the belt, the contact pressure of the pressure roller can be reduced, wherein good force transmission is nevertheless achieved between the belt and the spinning rotor. The load on the spinning rotor between the two bearing points is reduced as a result, and so the flexing work in the support disks and, therefore, the energy consumption of the spinning device can be reduced. It is also particularly advantageous, in this case, that the radial bearing load of the support disk bearing is also reduced as a result and, therefore, the service life of the bearings is extended. Since the friction coefficient-increasing lining is made of an elastomeric material, which has a particularly favorable friction coefficient relative to the driving belt, the slip between the belt and the rotor shaft and, therefore, the energy consumption and the wear of the belt can be reduced to a particularly great extent. In addition, such materials have favorable damping properties and the manufacture of the spinning rotor can be carried out particularly cost-effectively as compared to a coating comprising other friction coefficient-increasing materials.
According to one embodiment of the invention, it is advantageous when the lining has an overall width which is less than the width of the belt provided for driving the spinning rotor. As a result, the lateral edge areas of the belt do not rest on the lining, but rather on the base material of the rotor shaft, whereby the lining is protected against damages caused by the belt.
According to a first embodiment of the invention, the lining can be continuously applied across the entire effective width of the lining. According to another embodiment, it is also conceivable, however, that the lining is applied onto the rotor shaft in the form of multiple strips situated next to one another and spaced apart from one another relative to the axial direction of the rotor shaft. It is advantageous in this case that the rotor shaft having such a design undergoes less weakening.
Moreover, it is advantageous when the lining has a lining thickness of at most 1 mm, preferably at most 0.75 mm and, particularly preferably, at most 0.5 mm. The flexing work in the rotor drive and, therefore, the energy consumption, can be further reduced as a result.
Moreover, it is advantageous when the at least one recess is designed as at least one circumferential groove. In the simplest variant, the circumferential groove can be designed as a rectangular groove in this case, into which the plastic material has been introduced, in particular, via vulcanization. The lining is subjected to only slight wear as a result. In this case, it is also advantageous when the lining thickness is at most 1 mm, preferably at most 0.75 mm and, particularly preferably, at most 0.5 mm. The depth of the recess can be limited as a result and a weakening of the spinning rotor, which would reduce its characteristic frequency and result in undesirable oscillations during operation, can be avoided as a result. In this embodiment as well, the lining can be continuously applied or in the form of interspaced strips or rings.
In order to provide a preferably smooth outer surface of the rotor shaft and, therefore, a preferably planar support surface for the belt, it is furthermore advantageous when the rotor shaft, including the introduced lining, is ground. As a result, the force transmission between the belt and the rotor shaft can be improved and wear of the belt and of the rotor shaft can be reduced.
It is particularly advantageous when the lining is made of nitrile rubber or of hydrogenated acrylonitrile butadiene rubber. This not only has the friction and damping properties which are favorable for the operation of the spinning rotor, but is also antistatic, and so trash deposits in the area of the lining can be avoided. A close fit of the belt on the rotor shaft and, therefore, good force transmission between the belt and the rotor are further enhanced as a result. It is also conceivable, however, that the lining is made of a polyurethane elastomer or a natural rubber. These also have a favorable friction coefficient with respect to the drive belt and therefore provide for an energy-saving and low-wear operation of the open-end spinning device.
It is also advantageous when the rotor shaft is made of a metal, in particular, an aluminum material or a steel material. The heat, which still forms in the lining due to the flexing work between the belt and the lining, can be dissipated in a particularly favorable way as a result.
Such a spinning rotor comprising a rotor shaft which is provided with a friction coefficient-increasing material in its contact area can be utilized particularly advantageously for the energy-saving and low-maintenance operation of an open-end spinning device. Therefore, protection for an open-end spinning device comprising such a spinning rotor is also claimed.
Further advantages of the invention are described with reference to the exemplary embodiments represented in the following. Wherein:
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.
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.
It is therefore proposed to provide the rotor shaft 2 of the spinning rotor 1 with an elastomeric, friction coefficient-increasing lining.
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
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.
Finally,
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.
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.
1. spinning rotor
2. rotor shaft
3. belt
4. open-end spinning device
5. recess
6. rotor cup
7. contact area
8. lining
9. wedge gap
10. support disk
11. axial bearing
12. bearing block
13. support disk bearing
14. shaft
15. lateral edges of the belt
b overall width of the lining
B width of the belt
d lining thickness
Number | Date | Country | Kind |
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10 2016 108 859.5 | May 2016 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2017/060856 | 5/8/2017 | WO | 00 |