SPINNING DEVICE, ROTOR SPINNING MACHINE, AND METHOD FOR PREVENTING THE ACCUMULATION OF FIBRES IN A SPINNING DEVICE

Abstract

A spinning device for producing a yarn from a fiber material, a rotor spinning machine having at least one spinning device, and a method for preventing the accumulation of fibers inside a rotor housing of a spinning device. The spinning device has a rotor housing, a spinning rotor arranged inside the rotor housing and revolving at high speed during the spinning operation, and a rotor housing lid arranged on the rotor housing for opening and closing the rotor housing, wherein a device for generating at least one flow of sealing gas is also arranged, at least in portions, inside the rotor housing in a region of the rotor housing at the rear of the spinning rotor, in order to prevent fiber material and/or a loop of fibers getting behind the spinning rotor when the spinning rotor is braked and/or the rotor housing lid is opened.

Description

The invention relates to a spinning device for producing a yarn made of a fiber material, to a rotor spinning machine having at least one spinning device, and to a method for preventing the accumulation of fibers in a rotor housing of a spinning device.

Various spinning devices are known from the prior art, and are used for producing a yarn from a fiber material. In an open-end rotor spinning machine, singulated textile fibers are typically fed in a plurality of spinning devices formed as spinning boxes to a spinning rotor revolving at high speed during spinning operation, and are spun there into a yarn which is then pulled off the spinning rotor by means of a vacuum. The spinning device has a rotor housing within which the spinning rotor is arranged. A rotor housing lid is typically provided for opening and closing the rotor housing.

During the spinning operation, most of the textile fibers supplied in the spinning rotor are spun in the spinning rotor to form a yarn, and the small number of released individual fibers not spun into the yarn are removed from the region of the spinning rotor by means of the vacuum. However, when the spinning rotor is braked—for example, for opening the rotor housing—the rotor speed is no longer sufficient to keep the textile fibers being spun in the rotor groove of the spinning rotor. In addition, the vacuum must also be deactivated to open the rotor housing. Both of these things have the result that fiber material can spread out within the interior of the spinning device. In particular, a loop of fibers in the spinning rotor—a so-called donut—can become detached during the braking of the spinning rotor. In this case, fiber material, or the loop of fibers, can pass into an area behind the spinning rotor, and can contaminate the mount point of the spinning rotor, or wind themselves up, which typically results in a failure of the rotor spinning machine after a short time. This problem occurs in all spinning devices of a rotor spinning machine. However, this is particularly problematic in spinning devices with a single drive of the spinning rotor and/or with a contactless magnetic mount, since in this case an ingress of fiber material or a loop of fibers into the bearing air gap, or a winding around the spinning rotor axle, immediately leads to a failure of the spinning device when the spinning rotor is accelerated into rotation again.

For this purpose, the document DE 10 2015 016 594 A1 has proposed to deactivate the vacuum when the spinning rotor is braked at a rotational speed of the spinning rotor at which a loop of fibers is still held in the spinning rotor, and to pivot the spinning rotor through an at least partial opening of the rotor housing such that the loop of fibers can fall out of the rotor groove of the spinning rotor during further braking of the spinning rotor. Subsequently, the vacuum is activated again in order to suction off the loop of fibers produced from the spinning rotor, and the fiber material. However, this solution of the prior art has the disadvantage that, for a period of time, the rotational speed of the spinning rotor is no longer sufficient to keep the loop of fibers in the spinning rotor; and on the other hand, the vacuum is not yet activated again, so that it is not completely ensured that the loop of fibers cannot reach the region behind the spinning rotor. In addition, the weight of the loop of fibers and also the position of the loop of fibers produced from the spinning rotor varies, so that a sufficient volumetric flow cannot be generated in any case by means of the vacuum in order to reliably remove the loop of fibers and the fiber material from the spinning device. In this solution of the prior art, operational interruptions can thus occur due to the formation of wound loops or bearing point contamination.

The invention is therefore based on the object of providing a spinning device, a rotor spinning machine, and a method which enable particularly reliable and error-free operation irrespective of the number of interruptions in the spinning operation.

The object is achieved according to the invention by a spinning device according to claim 1, a rotor spinning machine according to claim 7, and a method for preventing the accumulation of fibers within a rotor housing of a spinning device according to claim 9. Advantageous further embodiments of the invention are given in the dependent claims.

The spinning device according to the invention for producing a yarn made of a fiber material has a rotor housing, a spinning rotor arranged within the rotor housing and revolving at high speed in spinning operation, and a rotor housing lid arranged on the rotor housing for opening and closing the rotor housing, wherein a device for generating at least one flow of sealing gas is also arranged at least in portions within the rotor housing in a region of the rotor housing behind the spinning rotor or at the rear of the spinning rotor, in order to prevent fiber material and/or a loop of fibers from getting behind the spinning rotor when the spinning rotor is braked and/or when the rotor housing lid is opened.

The invention further relates to a rotor spinning machine having at least one spinning device according to the invention, and preferably a plurality of spinning devices according to the invention, in particular preferably identical to one another.

The method according to the invention for preventing the accumulation of fibers within a rotor housing of a spinning device with a spinning rotor arranged within the rotor housing and revolving at high speed in spinning operation and a rotor housing lid arranged on the rotor housing for opening and closing the rotor housing has the method step of, directing a flow of sealing gas toward a region of the rotor housing behind the spinning rotor and/or to the region at the rear of the spinning rotor and/or rear wall of the spinning rotor before the rotor housing is opened and/or when the rotating spinning rotor is braked, in particular for a subsequent opening of the rotor housing, in order to prevent fiber material and/or a loop of fiber from getting behind the spinning rotor. The directing of the flow of sealing gas takes place in particular preferably by means of a device according to the invention for generating at least one flow of sealing gas.

The spinning device can first be any device or structural unit for producing threads, yarns or twisted yarns. The spinning device is preferably a spinning box, in particular a rotor spinning machine and particularly preferably an open-end rotor spinning machine. The spinning machine in this case can have only one, or more, spinning stations provided in each case for producing a thread, wherein each spinning station is particularly preferably formed as a spinning device and/or as a spinning box, and very particularly preferably has in each case precisely one spinning rotor.

A yarn produced and/or the thread produced within the context of the invention is a fiber strand which is preferably formed from individual fibers, wound around one another. The fibers can be formed from a natural material, such as wool or cotton, and/or from a synthetic material, such as polyester or polyether sulfone. The fiber material is preferably supplied to the spinning device in the form of a fiber web, also called a card sliver, and the individual fibers are preferably singulated before the spinning.

The rotor housing basically surrounds the spinning rotor rotating during the spinning operation at high rotational speed, and is preferably subjected to a vacuum in the spinning operation. In order to open the rotor housing and to be able to reach the spinning rotor, the rotor housing according to the invention has a rotor housing lid which is preferably mounted pivotably on the rotor housing. For opening and closing the rotor housing, the rotor housing lid is preferably movable and particularly preferably pivotable between an open and a closed position. Furthermore, the spinning rotor is preferably accessible in the open position of the rotor housing lid and/or substantially completely covered and/or inaccessible to a user in the closed position.

According to the invention, a device for generating at least one flow of sealing gas is provided, which device is basically provided to deliver at least one gas flow in a defined direction. The device for generating at least one flow of sealing gas preferably has at least one gas outlet opening and in particular a gas outlet nozzle, which can in particular be part of a blowing channel. In this case, each blowing channel basically has at least one such gas outlet opening or one gas outlet nozzle. The device for generating at least one flow of sealing gas should accordingly preferably prevent a formation of wound fibers and/or a shutdown due to a formation of wound fibers, or due to a contamination of the bearing, especially when the spinning rotor is restarted. Alternatively or additionally, the device for generating at least one flow of sealing gas should prevent accretion on the bearing of the spinning rotor in the long term.

Particularly preferably, the device is provided to emit a plurality of flows of sealing gas at the same time, and/or to block off/protect a region from fiber material and/or against a loop of fibers by means of gas flows directed toward the region. This is preferably done by one or more flows of sealing gas flowing away from the region to be protected. The flow of sealing gas is preferably a flow of compressed gas, and particularly preferably a compressed air flow.

The region to be protected by the flows of sealing gas and/or the region toward which the flows of sealing gas are directed preferably is a region on and/or behind the rear of the spinning rotor and/or the rear wall of the spinning rotor. Particularly preferably, the region to be protected extends between the rear wall of the spinning rotor and the opposite wall of the rotor housing. Particularly preferably, the region to be protected also encloses a bearing of the spinning rotor. Very particularly preferably, the flow of sealing gas flows around the entire circumference of the spinning rotor from the rear side thereof.

According to the invention, the device for generating at least one flow of sealing gas is arranged at least in portions within the rotor housing in a region of the rotor housing behind the spinning rotor and/or at the rear of the spinning rotor in order to be able to protect this region. For instance, only gas outlet openings or gas outlet nozzles may be directed into the interior of the rotor housing, while the remaining components of the device can be arranged in the rotor housing wall and/or outside the rotor housing, for generating at least one flow of sealing gas. It is furthermore preferred that the device is arranged in the interior of the rotor housing only on the side of the rotor housing facing the rear of the spinning rotor, and optionally in the material of the rotor housing and/or outside of the rotor housing. In addition, the device for generating at least one flow of sealing gas can be formed, in portions or completely, as a single piece with the rotor housing.

Fiber accumulations, and in particular loops of fibers, are particularly formed if fiber material not drawn-off during spinning remains in the spinning rotor, wherein these accumulations of fibers, and in particular loops of fibers, can then pass behind the spinning rotor when the rotor housing is opened and/or when the vacuum is deactivated. Fiber accumulations are in particular so-called donuts, i.e., an annular fiber composite and/or a loop of fibers which forms during the operation of the spinning rotor and can, in particular, pass from the spinning rotor into the rotor housing when the spinning rotor is stopped, or below a minimum rotational speed. In principle, however, the accumulation of fibers can have any shape and size, and in particular can be formed from any number of individual fibers.

A preferred embodiment of the spinning device according to the invention for producing a yarn has at least one blowing channel arranged on the rotor housing, and/or directed toward the rear of the spinning rotor, which blowing channel makes it possible to direct a flow of sealing gas to a region that is to be protected. In this case, the blowing channel first is understood to mean only the part of the device for generating at least one flow of sealing gas which directs the flow of sealing gas directly toward the rear of the spinning rotor. In this case, the blowing channel can also extend in any desired manner in the interior of, and/or behind, the rotor housing, and/or can be connected to another device, further compressed air lines or channels, or can be connected to further blowing channels of the same spinning device or a further spinning device. The blowing channel(s) is/are preferably arranged in a region opposite the spinning rotor and/or the rear of the spinning rotor, in particular on the rotor housing. Furthermore, the device for generating at least one flow of sealing gas is preferably formed as a single piece with the rotor housing. Alternatively or additionally, the blowing channel preferably runs within the wall of the rotor housing.

Although a protective function can in principle already be achieved by means of a single blowing channel, a device for generating at least one flow of sealing gas is preferred which has at least two, preferably between 3 and 12, particularly preferably between 4 and 10, and very particularly preferably between 6 and 8 blowing channels. Preferably, each blowing channel has exactly one opening directed toward the spinning rotor, and in particular toward the rear of the spinning rotor, which opening is formed in order to direct the flow of sealing gas toward the rear side of the spinning rotor.

An advantageous embodiment of the spinning device for producing a yarn furthermore provides that the blowing channel(s) is/are arranged in a circular and/or uniformly distributed manner on the rotor housing around an axis of rotation of the spinning rotor. A uniform arrangement refers in particular to the same distance from the spinning rotor axis and/or to the same distance from adjacent blowing channels and/or an identically spaced arrangement on a circle, in particular about the spinning rotor axis. The blowing channels are preferably arranged on an inner wall of the rotor housing and/or on a region of the rotor housing covered by the spinning rotor in relation to the opening of the rotor housing or in relation to the rotor housing lid. Further preferably, the blowing channels are arranged—in relation to the opening of the rotor housing or in relation to the rotor housing lid—behind the spinning rotor.

Likewise preferably, the distance of the blowing channel(s) from the axis of rotation of the spinning rotor is less than the radius of the spinning rotor, particularly preferably less than 90%, very particularly preferably less than 80%, and particularly preferably less than 75% of the radius of the spinning rotor. Alternatively or additionally, the distance of the blowing channel(s) from the axis of rotation of the spinning rotor is greater than 10%, particularly preferably greater than 25%, very particularly preferably greater than 50%, and particularly preferably greater than 75% of the radius of the spinning rotor.

In a preferred development of the spinning device according to the invention for producing a yarn, the angle of the blowing channel(s) in each case, at least in the region provided for the flow of sealing gas to exit, relative to the axis of rotation of the spinning rotor, is between 0° and 45°, preferably between 0° and 30°, and particularly preferably between 5° and 20°, so that the flow of sealing gas is directed in each case toward the outer edge of the spinning rotor, and/or the sealing gas flows along the rear of the spinning rotor in the direction of the outer edge of the spinning rotor. In addition, the blowing channel can also be aligned parallel to the spinning rotor axis. The angle of the blowing channel is the angle between the central longitudinal axis of the spinning rotor axis and the central longitudinal axis of the opening and/or the end region of the blowing channel for the exit of the flow of sealing gas.

A further preferred embodiment of the spinning device for producing a yarn provides that the blowing channels are connected to a ring-shaped air distributor which is preferably formed as a structural unit, or integrally with the rotor housing, and/or is connected to a compressed air connection on the outside of the rotor housing. Particularly preferably, the air distributor is formed completely integrally with the rotor housing. Alternatively, however, the air distributor can also be formed as a component arranged on the rotor housing, and/or can form a part of the rotor housing. In addition, the air distributor can be arranged in portions or completely within and/or outside the rotor housing.

Although a rotor spinning machine with a central drive for a plurality of spinning devices, and in particular a plurality of spinning rotors, is also conceivable, the device according to the invention for generating at least one flow of sealing gas is preferably used in one or more spinning devices of a rotor spinning machine, in which each spinning rotor is driven individually, and/or preferably contactlessly, in particular magnetically. In the case of a contactless mounting of the spinning rotor, it is particularly important to avoid contamination with fiber material in the region of the mount point, since otherwise a failure occurs when the spinning rotor is restarted. The drive of the spinning rotor is in particular preferably an electric motor single drive.

An advantageous embodiment of the method for preventing the accumulation of fibers within a rotor housing of a spinning device provides that the flow of sealing gas is deactivated during the spinning process for producing a yarn from a fiber material by means of the spinning rotor, and/or the flow of sealing gas is activated at a predetermined time, preferably between 0.5 s and 10 s, particularly preferably between 1 s and 5 s, and very particularly preferably between 1 s and 2 s before the rotor housing is opened. The rotor housing is preferably opened automatically. Alternatively or additionally, manual opening after an automatic unlocking of an openable rotor housing lid is also possible, wherein the flow of sealing gas is particularly preferably activated at a predetermined time interval before the unlocking and/or automatic opening.

Alternatively or additionally, an embodiment of the method for preventing the accumulation of fibers within a rotor housing of a spinning device is also preferred in which the flow of sealing gas is deactivated during the spinning process for producing a yarn from a fiber material by means of the spinning rotor, and/or the flow of sealing gas, when the spinning rotor is braked, is activated as a function of the rotor speed, preferably when a rotor speed drops below 50,000 1/min, particularly preferably 30,000 1/min, and very particularly preferably 20,000 1/min, since, starting at this number of revolutions, the fiber material is no longer sufficiently held in a loop of fibers of the spinning rotor, and thus can get behind the spinning rotor and/or the rear of the spinning rotor.

In addition, it is preferred that the flow of sealing gas is deactivated at a predetermined point in time after the rotor housing has been opened, preferably between 0.5 s and 10 s, particularly preferably between 1 s and 5 s, and very particularly preferably between 1 s and 2 s. Alternatively, the flow of sealing gas can also remain activated as long as the rotor housing lid is open, and is deactivated again only when the rotor housing is completely closed and/or when the spinning rotor is started up, in particular when a minimum speed of rotation is reached, preferably of 50,000 1/min, particularly preferably 30,000 1/min, and very particularly preferably of 20,000 1/min.

In principle, the spinning process takes place with a closed rotor housing and a vacuum applied to the rotor housing. There is also a relationship between the application of the vacuum and the risk that fiber material, and in particular a loop of fibers, passes into an area behind the spinning rotor. Accordingly, a development of the method for preventing the accumulation of fibers within a rotor housing of a spinning device is preferred in which the flow of sealing gas is activated before a vacuum within the rotor housing required for spinning operation is shut off. Alternatively, the activation of the flow of sealing gas can also take place simultaneously with the deactivation of the vacuum.

An embodiment of the device according to the invention for generating at least one flow of sealing gas in a spinning station is explained in more detail below with reference to the drawings. In the drawings:

FIG. 1 is a perspective view of a rotor housing, with a spinning rotor and a device for generating at least one flow of sealing gas of a spinning device, and

FIG. 2 is a perspective sectional view of the rotor housing shown in FIG. 1, with a device for generating at least one flow of sealing gas.

A spinning device of a rotor spinning machine, shown in portions in FIG. 1, has at least one spinning rotor 2 revolving at high speed during the spinning operation, which spinning rotor is arranged within a rotor housing 1. For the spinning operation, the rotor housing 1 is closed and a vacuum is applied. In order to be able to open the rotor housing 1, a rotor housing lid is provided which is arranged pivotably on the rotor housing 1.

For spinning a yarn from a fiber material, singulated fiber material is supplied to the spinning rotor 2. If the spinning operation is to be interrupted, the spinning rotor 2 is braked, so that the rotor housing 1 can then be opened. However, if the spinning rotor 2 falls below a number of revolutions that typically lies in the range between 50,000 1/min and 20,000 1/min, the centrifugal forces no longer suffice to keep the fiber material located in the spinning rotor 2 therein, so that a fiber accumulation, in particular a loop of fibers, can reach the interior of the rotor housing 1 of the spinning rotor 2. If the loop of fibers is in a region in front of the spinning rotor 2 or between the spinning rotor and an openable rotor housing lid, this is unproblematic, since the loop of fibers is removed when the rotor housing 1 is opened. If, on the other hand, the loop of fibers or the accumulation of fibers approaches a region behind the spinning rotor 2, and in particular moves into the region of the spinning rotor axis, an electric spinning rotor drive and/or a magnetic spinning rotor bearing, a malfunction can occur, in particular when the spinning rotor 2 is restarted.

In order to prevent this, a device 3 for generating a flow of sealing gas is arranged behind the spinning rotor 2 in the region of the rotor housing 1 (see FIG. 1), by means of which device a plurality of flows of sealing gas can be directed toward a region behind the spinning rotor when the spinning rotor is braked 2, so that no loop of fibers and no accumulations of fibers can get into this region protected in this way. For this purpose, eight blowing channels 5 of the device 3 for generating a flow of sealing gas are arranged in the correct direction along a circle around the spinning rotor axis on the rotor housing 1 downstream of the spinning rotor 2 (see FIG. 2) in such a way that, by means of each of the blowing channels 5, a flow of sealing gas can be directed toward the rear of the spinning rotor 4, so that the flows of sealing gas flow along a region between the rear wall of the rotor housing 1 and the rear of the spinning rotor 4, and then flow further radially along the rear of the spinning rotor 4 toward the front side of the spinning rotor 2, so that no loops of fibers can reach this region. In this case, an outlet opening of each blowing channel 5 is arranged at an angle of about 30° with respect to the axis of rotation of the spinning rotor 2, and radially away from the spinning rotor center.

To supply the individual blowing channels 5 with compressed air, these are connected in the interior of the wall of the rotor housing 1 to a ring-shaped air distributor 6 which is supplied via a compressed air connection 7 arranged on the outside of the rotor housing 1. All blowing channels 5 and in particular all openings of the blowing channels 5 for the discharge of sealing gas are accordingly formed identically to one another and/or have a round cross section.

LIST OF REFERENCE SIGNS

• • 1 Rotor housing
  • 2 Spinning rotor
  • 3 Device for generating a flow of sealing gas
  • 4 Rear of the spinning rotor
  • 5 Blowing channel
  • 6 Air distributor
  • 7 Compressed air connection

Claims

1. A spinning device for producing a yarn from a fiber material, the spinning device comprising:

a rotor housing;

a spinning rotor arranged within the rotor housing and revolving at high speed during spinning operation;

a rotor housing lid arranged on the rotor housing for opening and closing the rotor housing; and

a flow device arranged at least in portions within the rotor housing for generating at least one flow of sealing gas in a region at a rear of the spinning rotor, in order to prevent fiber material and/or a loop of fibers from entering the spinning rotor when the spinning rotor is braked and/or when the rotor housing lid is opened.

2. The spinning device for producing the yarn according to claim 1, wherein the flow device for generating the at least one flow of sealing gas has at least one blowing channel arranged on the rotor housing and directed toward the rear of the spinning rotor.

3. The spinning device for producing the yarn according to claim 1, wherein the flow device has between 6 and 8 blowing channels for generating the at least one flow of sealing gas.

4. The spinning device for producing the yarn according to claim 3, wherein the blowing channels are arranged on the rotor housing in a circular and/or uniform manner about an axis of rotation of the spinning rotor.

5. The spinning device for producing the yarn according to claim 3, wherein an angle of the blowing channels in each case in relation to an axis of rotation of the spinning rotor is between 0° and 45°.

6. The spinning device for producing the yarn according to claim 3, wherein the blowing channels are connected to a ring-shaped air distributor which is formed as a structural unit together with the rotor housing, and is connected to a compressed air connection on an outside of the rotor housing.

7. A rotor spinning machine having at least one spinning device according to claim 1.

8. The rotor spinning machine according to claim 7, wherein each spinning rotor is individually driven and/or mounted contactlessly.

9. A method for preventing the accumulation of fibers within a rotor housing of a spinning device, the method comprising:

arranging a spinning rotor within the rotor housing and revolving the spinning rotor at high speed during spinning operation;

arranging a rotor housing lid on the rotor housing for opening and closing the rotor housing; and

before the rotor housing is opened and/or when the spinning rotor is braked, directing a flow of sealing gas to a region of the rotor housing at a rear of the spinning rotor in order to prevent fiber material and/or a loop of fibers from getting behind the spinning rotor.

10. The method for preventing the accumulation of fibers within the rotor housing of the spinning device according to claim 9, further including deactivating the flow of sealing gas during a spinning process for producing a yarn from a fiber material by the spinning rotor, and activating the flow of sealing gas at a predetermined time between 1 second and 5 seconds before the rotor housing is opened.

11. The method for preventing the accumulation of fibers within the rotor housing of the spinning device according to claim 9, further including deactivating the flow of sealing gas during the spinning process for producing a yarn from a fiber material by the spinning rotor, and activating the flow of sealing gas when the spinning rotor is braked, as a function of the rotor speed, when a rotor speed drops below 20,000 1/min.

12. The method for preventing the accumulation of fibers within the rotor housing of the spinning device according to claim 9, further including deactivating the flow of sealing gas at a predetermined time between 1 second 5 seconds after the rotor housing has been opened.

13. The method for preventing the accumulation of fibers within the rotor housing of the spinning device according to claim 9, wherein the flow of sealing gas is activated before a vacuum applied to a spinning operation within the rotor housing is shut off.