CN114829688B

CN114829688B - Wire guide disc

Info

Publication number: CN114829688B
Application number: CN202080086938.3A
Authority: CN
Inventors: M·施勒特; M·埃勒; P·施泰因克
Original assignee: Stc Textile Co
Current assignee: Stc Textile Co
Priority date: 2019-12-17
Filing date: 2020-10-20
Publication date: 2023-08-01
Anticipated expiration: 2040-10-20
Also published as: WO2021123941A1; CN114829688A; DE102019134639B4; DE102019134639A1; EP4025729A1

Abstract

The invention relates to a wire guide disk having a wire guide disk drive motor, a motor support, a rotatably mounted drive shaft which is driven or drivable by the wire guide disk drive motor and is arranged centrally in the wire guide disk and is oriented in the axial direction of the wire guide disk, wherein the rotor of the wire guide disk drive motor is fixed to the circumferential part of the drive shaft, the wire guide disk further having a wire guide disk cover connected to the drive shaft, a wire guide disk cover heater surrounded by the wire guide disk cover, and at least one cooler, wherein according to the invention at least a part of the wire guide disk drive motor and of the motor support and at least one flow channel of the cooler are arranged in a part of the wire guide disk which is surrounded by the wire guide disk cover, in which part the wire guide disk cover heater is also provided.

Description

Wire guide disc

Technical Field

The invention relates to a wire guide disk having a wire guide disk drive motor, a motor support, a rotatably mounted drive shaft which is driven or drivable by the wire guide disk drive motor and is arranged centrally of the wire guide disk and is oriented in the axial direction of the wire guide disk, wherein the rotor of the wire guide disk drive motor is fixed to the circumferential section of the drive shaft, and the wire guide disk has a wire guide disk cover connected to the drive shaft, a wire guide disk cover heater surrounded by the wire guide disk cover, and at least one cooler.

Background

Yarn guides of this type are driven rotating yarn production rollers used in the textile industry, in particular in spinning mills. At least one thread, at least one fiber or at least one sliver is guided on the heated mantle surface of the godet. In practice, a plurality of yarn guide discs arranged offset to one another in different planes and running at different rotational speeds are often combined to form a drawing roller device. Typically, the godet cover rotates at a circumferential speed of up to 5000 meters/minute.

Heating of the godet is necessarily required for filament production. The cylindrical wire guide plate is heated from the inside by a wire guide plate cover heater, which is usually designed as an induction heater, whereby moisture can be carried out from the threads, fibers or strips guided on the wire guide plate cover.

Typically, the temperature of the guidewire disc is measured by means of at least one thermal sensor and transmitted to the guidewire disc controller by means of a measurement transmission mechanism.

The wire guide disc cover is put into rotation by means of a wire guide disc drive motor. For this purpose, it is common in the prior art, for example, as in publication DE102014006854A1, to provide a hub at one end of the wire guide disc cover, which is fixedly connected to the shaft end of the drive shaft, which shaft end protrudes from the bearing housing, wherein a wire guide disc drive motor, which is designed as an electric motor, is integrated into the bearing housing and is connected to the drive shaft at its bearing end.

However, the high temperatures used in wire guide plate heaters are a technical disadvantage for the wire guide plate drive motor, the wire guide plate support member and the measurement value transmission mechanism.

By separating the wire guide disk drive motor from the part of the glowing wire guide disk cover in the prior art, the wire guide disk drive motor, which itself runs hot during operation, on the one hand does not become hotter and on the other hand can be cooled appropriately by means of a cooler. The coolers for the guide wire disc drive motors described in publications EP0424867A1 and EP0454618B1 use cooling air. Air cooling may be supported by an externally driven fan.

It is particularly advantageous to use a cooling liquid to cool the motor. It is known to mount the wire guide disk drive motor and the support member of the wire guide disk in a water-cooled housing located remotely from the wire guide disk heater.

In publication EP1126061A2, in which the wire guide disc drive motor is also located remotely from the wire guide disc heater, the support member of the wire guide disc, by means of which the wire guide disc drive shaft is rotatably supported, is cooled by means of a combination of air cooling and water vapor cooling.

In the case of the known wire guide disk, the respective measuring value transmission means used are also arranged remote from the wire guide disk heater. It is typically air-cooled.

However, this design also has the disadvantage that a large structural length of the wire guide disk is accompanied by a comparatively small effective area, which leads to considerable space requirements, especially in the case of elongate wire guide disks, and that the wire guide disk cover is subjected to a large mechanical load and the associated support for the wire guide disk cover is worn away in advance when the wire guide disk cover is mounted away from the wire guide disk heater.

In addition, when different temperature control systems are used to cool several components of the guidewire tray, multiple energy sources are then required, which in turn results in greater space requirements and higher maintenance and service costs.

Disclosure of Invention

The object of the present invention is therefore to create a guide wire disc which requires less space and is less abrasive than the solutions known from the prior art.

The object is achieved by a wire guide disk having a wire guide disk drive motor, a motor support, a rotatably mounted drive shaft which is driven by the wire guide disk drive motor or can be driven and is arranged centrally in the wire guide disk and is oriented in the axial direction of the wire guide disk, wherein a rotor of the wire guide disk drive motor is fastened to a peripheral surface of the drive shaft, the wire guide disk further having a wire guide disk jacket connected to the drive shaft, a wire guide disk jacket heater surrounded by the wire guide disk jacket, and at least one cooler, wherein at least a part of the wire guide disk drive motor and the motor support and at least one flow channel of the cooler are arranged in a part of the wire guide disk in which the wire guide disk jacket heater is also provided, which part is surrounded by the wire guide disk jacket.

Preferably, the entire wire guide disk drive motor is arranged in a wire guide disk portion which is cooled by at least one flow channel of the cooler, which is surrounded by the wire guide disk cover and is also provided with a wire guide disk cover heater.

The present invention is directed away from the prior art, and attempts have always been made to arrange the wire guide disk drive motor as far away from the wire guide disk cover heater as possible in order to avoid additional heating of the wire guide disk drive motor, which would otherwise be heated strongly by the wire guide disk cover heater during operation. In contrast to the prior art, in the wire guide disk of the invention at least a part of the wire guide disk drive motor, preferably the entire wire guide disk drive motor, is even arranged in the portion of the wire guide disk that is heated by the wire guide disk cover heater.

The wire guide disc drive motor is therefore no longer arranged at one end of the wire guide disc cover surrounding the wire guide disc cover heater as in the prior art. Instead, space is saved by arranging the wire guide disc drive motor in the wire guide disc cover and the wire guide disc cover heater according to the invention. The separate space can be used, for example, for shortening the overall length of the guide wire disc in the case of a limited mounting surface, or for increasing the effective area of the guide wire disc in the case of a uniform mounting surface.

In the godet according to the invention, the motor cooler is realized by a fluid cooler having at least one flow channel, which extends between the godet drive motor and the godet cover heater. The fluid cooler in particular causes waste heat of the guide wire disk drive motor to be dissipated, since it is arranged in spatial immediate proximity thereto. Here, the flow channel or the flow channels may be formed in the carrier material.

The fluid cooler also removes heat from the motor support and preferably from the measurement value transmission of the wire guide disk. In the present invention, it is a unified temperature control system that extends through the wire guide disk drive motor, motor support and preferably the wire guide disk's measurement delivery mechanism and is located in one area within the wire guide disk cover and wire guide disk cover heater.

The guide wire disc according to the invention is designed such that the support for the guide wire disc drive motor is also arranged in the guide wire disc part enclosed by the guide wire disc cover, i.e. in the part where the load is present on the guide wire disc. There is thus no lever arm that increases the resulting forces acting on the support. In the present invention, the motor support serves here as a guide wire disk housing support.

In a preferred embodiment of the yarn guide disk according to the invention, at least a part of the yarn guide disk drive motor and at least a part of the motor support are arranged in the interior of the carrier, wherein the at least one flow channel extends through the material of the carrier between the yarn guide disk drive motor and the yarn guide disk cover heater.

Since the wire guide disc drive motor is according to the invention located in the part of the wire guide disc where the wire guide disc cover heater is also located, in the embodiment of the invention where the wire guide disc drive motor is located in the inner cavity of the carrier, the wire guide disc cover heater is arranged around at least a part of the carrier. A portion of the carrier at least partially shields the wire guide disk drive motor from heat radiation from the wire guide disk cover heater.

The carrier forms a stable receptacle for the fluid cooler and thus physically and thermally separates the wire guide disc drive motor from the wire guide disc cover heater.

The at least one flow channel can be integrated in the carrier in such a way that the fluid cooler extends at least over the length of the carrier, so that the motor and the guide wire disc housing support, the respective seal and the measured value transmission of the guide wire disc are cooled by the same fluid cooler of the guide wire disc drive motor.

The carrier does not rotate. In the interior of the carrier, the connecting wire can advantageously be guided to the guide wire disc drive motor. The stator of the wire guide disc drive motor can be well mounted in the carrier. That is, the position of the wire guide disc drive motor can be well fixed. In addition, the carrier provides additional stabilization of the wire guide disc and protection of the wire guide disc drive motor and motor support. The arrangement also saves space.

Preferably, the carrier is designed rotationally symmetrical. The guide wire disk drive motor and the motor support are then well mounted in the cylindrical interior of the carrier. The rotationally symmetrical shape of the carrier is adapted to the shape of the wire guide disc. However, the carrier may in other embodiments of the invention be designed, for example, in the form of a plate or a bulge.

The carrier may be designed in one piece or made up of a plurality of layers and/or components.

In an advantageous embodiment of the invention, the cooler has a coil with inlet and return openings for the cooling fluid arranged side by side. By designing the tube forming the at least one flow channel in a spiral shape, the cooling liquid can be guided along around the entire circumference of the guidewire disk drive motor. The coil forms a closed cooling cycle with a tube interface of inlet and return ports at the head of the coil and an elbow at the end of the coil. In the spiral running direction of the spiral tube, the inlet is located beside the return opening, thus ensuring uniform cooling.

It is also advantageous if the inlet and return openings of the coil are at the same mutual distance.

It has proven to be particularly advantageous here if the inlet and outlet openings of the cooler are located side by side in the same cylindrical plane of the carrier and/or if the inlet and outlet openings of the cooler are located side by side in planes of the carrier which are stepped relative to one another and/or if the inlet and outlet openings of the cooler are located on a conical hood plane of the carrier. That is, the inlet is located directly beside the return port on the same diameter and/or the inlet and return ports are located at mutually offset diameter steps and/or the inlet and return ports taper together or apart. This results in a very long cooling system adapted to the other dimensions of the guide wire disc, whereby the guide wire disc as a whole can be designed to have a compact structure.

Preferably, the coil is a steel tube that is cast into the carrier material. The steel pipes have a long service life and good heat conducting properties, thus providing advantageous cooling over a long period of time and almost maintenance-free.

In a development of the guide wire disc according to the invention, at least one further coil, in which a medium other than a cooling fluid is guided, extends parallel to the cooler coil within the carrier material and/or on the inner wall of the carrier. By means of another coil, for example, lubricant can be fed to parts of the guide wire disc, such as for example bearings.

Preferably, the carrier is composed of a metallic material and/or a mineral material. The carrier element, which is made of metal, such as aluminum or cast iron, has a good heat conducting property, whereby the temperature of the heated wire guide disc drive motor can be conducted away very effectively. Alternatively, the carrier may be composed of a plastic with good heat conducting properties.

While mineral carrier material may be used to achieve thermal isolation between the wire guide disc drive motor and the wire guide disc cover heater at least in part by means of the carrier. In order to nevertheless provide good heat dissipation of the waste heat of the wire guide disk drive motor by means of a fluid cooler integrated in the carrier, it is advantageous in this embodiment if the fluid cooler is arranged closer to the wire guide disk drive motor than to the wire guide disk cover heater and/or if good heat transfer elements, such as for example a metal jacket or a metal coating, are provided at least on the side of the carrier facing the wire guide disk drive motor.

The carrier is preferably designed with a carrier insert embedded in the portion of the wire guide disk surrounded by the wire guide disk cover and a carrier sleeve in which the wire guide disk cover is seated. The wire guide disc cover with the wire guide disc cover heater arranged therein can thus advantageously be crimped onto the carrier sleeve and the structure mounted thereto.

The wire guide plate cover heater can thus be mounted on the carrier, wherein the carrier material provides thermal insulation, so that the cooler integrated in the carrier only slightly cools the wire guide plate cover heater. In addition, it is possible in this configuration to form the wire guide disk cover heater separately and to conduct the contacts and then to integrate them appropriately into the wire guide disk, in particular into the gap between the wire guide disk cover and the carrier.

In addition or as an alternative to the fluid cooler, air cooling by means of at least one air duct formed in the carrier material and/or on the inner wall of the carrier can also be provided.

In an advantageous embodiment of the invention, a distance between the wire guide disk cover heater and the carrier is adjusted by means of at least one spacer, in which distance air is present. The gasket is preferably constructed of at least one material having poor thermal conductivity. For example, two teflon rings, which are arranged at a distance from one another, for example, are used as shims, which are fitted over the carrier part, on which the wire-guiding disk cover heater is placed.

Air located between the godet heater and the carrier is a poor thermal conductor. This makes it possible for the carrier to absorb a small amount of heat from the wire guide disk cover heater and thus to better conduct heat away from the wire guide disk drive motor. In addition, more heat generated by the wire guide disc cover heater may be transferred to the wire guide disc cover.

In a further embodiment of the invention, additional cooling is obtained in that on the drive shaft, a fan wheel is mounted in the carrier, which fan wheel rotates with the drive shaft. The fan wheel provides protection against heat from the wire guide disk drive motor and the wire guide disk support part, which heat arises as a result of the heat conduction of the wire guide disk cover via the drive shaft. The fan wheel is located below the carrier, within which a fluid cooler is integrated. By rotating the fan wheel, air vortices are present between the fluid cooler and the drive shaft, thereby reducing heat conduction via the drive shaft. The fan wheel may also be placed under the fluid cooler.

One or more thermal sensors are preferably provided in the guidewire disc, for example in the guidewire disc cover. At one end of the drive shaft, a connecting cable of the thermal sensor extends in a sensor value transmission means configured as a rotary transmission means, via which the measured temperature signal can be transmitted, for example, to an external control and/or evaluation unit of the guide wire disk.

In one suitable embodiment of the invention, the measuring-value transmission means has a rotatable part which is fixed to the drive shaft and a stationary part which is fixed in the carrier, wherein an air gap is present between the rotatable part and the stationary part of the measuring-value transmission means, via which air gap the signal transmission takes place.

Drawings

The invention will be described in detail below in connection with examples and the corresponding figures, without limiting the invention thereto, which are shown here:

FIG. 1 schematically illustrates a longitudinal cross-section of one embodiment of a guidewire disk of the present invention;

FIG. 2 schematically illustrates a top perspective view of a carrier of one embodiment of a godet of the present invention; and

fig. 3 schematically illustrates a perspective view of a cooling coil of one embodiment of a godet of the present invention.

Detailed Description

FIG. 1 illustrates a side cross-sectional view of one embodiment of a guidewire disk of the present invention.

The wire guide disc 1 has centrally a drive shaft 5 oriented in the axial direction R of the wire guide disc 1. The drive shaft 5 is rotatably mounted.

The drive shaft 5 is driven by or can be driven by the wire guide disc drive motor 2 of the wire guide disc 1. For this purpose, the rotor 21 of the guide wire disc drive motor 2 is fixed to the peripheral surface of the drive shaft 5 in the extension of the drive shaft 5, i.e. not at both ends thereof. Accordingly, the drive shaft 5 can rotate with the rotor 21 and be well held in its position.

The wire guide disc drive motor 2 is mounted by means of a motor support 4 mounted on a drive shaft 5.

In the embodiment shown, the motor support 4 has, in the longitudinal orientation of the wire guide disk 1, a first bearing 41 upstream of the rotor 21 of the wire guide disk drive motor 2 and a second bearing 42 downstream of the rotor 21 of the wire guide disk drive motor 2. The first bearing 41 and the second bearing 42 are ball bearings, respectively, in the embodiment shown. The rotor 21 of the wire guide disc drive motor 2 and the wire guide disc cover 7 are both mounted with the drive shaft 5 by means of bearings 41, 42.

The wire guide disc cover 7 of the wire guide disc 1 is connected to the drive shaft 5. In operation of the godet 1, at least one thread, at least one fiber and/or at least one sliver is guided on the outer circumferential surface of the godet cover 7. The at least one yarn, the at least one fiber and/or the at least one sliver is then wound around the godet cover 7.

The wire guide disc cover 7 is designed cylindrically. A wire guide plate cover heater 8 is provided on the inner side of the wire guide plate cover 7, whereby the wire guide plate cover 7 is heated during operation of the wire guide plate 1. The wire guide plate cover 7 encloses a wire guide plate cover heater 8 in the front portion B of the wire guide plate 1. I.e. the wire guide disc cover 7 is placed just above the wire guide disc cover heater 8.

The godet cover heater 8 is an induction heater in the illustrated embodiment. In particular, a 4 zone heater is used in the illustrated embodiment. Whereby different parts of the godet 1 can be heated differently. Alternatively, the godet cover heater 8 may have only one zone or have other numbers of zones.

The wire guide disc drive motor 2 is arranged in a part a of the wire guide disc 1 which part is part of a portion B of the wire guide disc 1 surrounded by the wire guide disc cover 7. Thus, the wire guide disc drive motor 2 is arranged in the same axial portion of the wire guide disc 1 to which the wire guide disc cover heater 8 is also mounted.

The second bearing 42 of the motor support 4 is also arranged in the part B of the wire guide disk 1 enclosed by the wire guide disk cover 7 and is therefore arranged directly in the region where the load occurs.

In the embodiment shown, the motor support 4 is also a godet cover support.

The wire guide disc drive motor 2 and the motor support 4 are arranged in an inner cavity of a carrier 9 of the wire guide disc 1. In the embodiment shown, the carrier 9 is designed rotationally symmetrical.

The stator 22 of the wire guide disc drive motor 2 is fixed to the inner wall of the carrier 9. The wire guide disc drive motor 2 is thus located together with its two bearing points in the wire guide disc housing 7.

The godet cover heater 8 is located above the carrier 9 and surrounds the carrier insert 91.

The rotor 21 of the wire guide disc drive motor 2 is held on the drive shaft 5 by means of the inner rings of the ball bearings 41, 42. The stator 22 of the wire guide disc drive motor 2 is held in the carrier bushing by means of the outer rings of the ball bearings 41, 42.

The carrier 9 has an annular cross section, i.e. is hollow in the interior, so that the guidewire disk drive motor 2 can be mounted therein. In the embodiment shown, the carrier 9 is composed of aluminum.

The carrier 9 comprises a carrier insert 91 having a smaller outer cross section and a carrier sleeve 92 having a larger outer cross section.

The carrier insert 91 has a length C. It is arranged in the portion of the wire guide disc 1 enclosed by the wire guide disc cover 7, wherein the carrier insert 91 is arranged around the drive shaft 5. Here, the carrier insert 91 is located between the wire guide disk drive motor 2 and the wire guide disk cover heater 8.

In the embodiment shown, two teflon rings 15,16 are arranged on the carrier 9 at a distance from each other, which teflon rings create a distance between the carrier 9 and the godet cover heater 8. Air 14 is located within the space.

The carrier sleeve 92 is located at the end side of the wire guide disc cover 7 and is therefore not in the part enclosed by the wire guide disc cover 7.

The motor cooler is integrated as a fluid cooler 3 in the embodiment shown into the material of the carrier 9, i.e. within the cylindrical wall of the carrier 9. The fluid cooler 3 now extends approximately over the entire longitudinal extension of the carrier 9. That is, in the embodiment shown, the fluid cooler 3 is arranged not only within the carrier insert 91 but also in the carrier sleeve 92. The fluid cooler 3 is thus in any case arranged in the part of the carrier 9 between the godet drive motor 2 and the godet cover heater 8.

Thus, the fluid cooling 3 is located in the portion enclosed by the wire guide disc cover 7 just like the wire guide disc drive motor 2 and the motor support 4.

In the embodiment shown, the fluid cooler 3 is a water cooler which is supplied with water via a water connection which protrudes into the guide wire disc 1 at a portion thereof remote from the guide wire disc cover 7.

By means of the carrier insert 91 extending between the wire guide disc drive motor 2 and the wire guide disc cover heater 8, the wire guide disc drive motor 2 is at least partly shielded from heat radiation by the wire guide disc cover heater 8 and is also cooled by means of the fluid cooler 3 extending within the material of the carrier insert 91.

The carrier 9 can be seen in the top perspective view of fig. 2. The carrier insert 91 is of cylindrical design and has a smaller diameter than the carrier sleeve 92. The carrier sleeve 92 interfaces with the carrier insert 91.

The fluid cooler 3 is in the embodiment shown constituted by a cooling coil 30, for example as shown in fig. 3.

The cooling coil 30 has a coil with an inlet 31 and a return 32 for the cooling fluid. In the embodiment shown, the inflow opening 31 and the return opening 32 are arranged next to one another, wherein they have the same mutual distance in the spiral course of the coil. At the head of the coil, pipe ports for the inlet port 31 and the return port 32 are provided, respectively. It is turned at one end 33 of the coil, whereby the inlet port 31 and the return port 32 are connected to each other here.

The inlet 31 and the return 32 of the cooler are located side by side in the same cylindrical plane of the carrier 9.

The coil is in the embodiment shown a steel tube which is poured into the material of the carrier 9.

In other embodiments of the invention, not shown, at least one further coil (in which a further medium, different from the cooling fluid, is guided) extends in the material of the carrier 9 and/or at the inner wall of the carrier 9, parallel to the cooler coils.

A thermal sensor 81 is provided in or below the godet cover 7. The connection cable of the thermal sensor 81 is connected to the measurement value transmission mechanism 80. The measured value transmission mechanism 80 has in the embodiment shown a rotatable part 82 fixed to the drive shaft 5 and a stationary part 84 fixed within the carrier 9. Between the rotatable part 82 and the stationary part 84 of the measurement value transmission means 80 there is an air gap 83, via which the signal transmission takes place.

A fan wheel 12, which rotates with the drive shaft 5, is arranged on the drive shaft 5 at one end of the carrier 9, but also in the carrier 9.

A seal 13 is provided on the drive shaft 5 between the bearing 42 and the fan wheel 12.

Claims

1. A wire guide disk (1), the wire guide disk (1) having a wire guide disk drive motor (2), a motor support (4), a rotatably mounted drive shaft (5), the drive shaft (5) being driven or drivable by the wire guide disk drive motor (2) and being arranged centrally of the wire guide disk (1) and oriented in the axial direction of the wire guide disk (1), wherein a rotor (21) of the wire guide disk drive motor (2) is fixed on a circumferential part of the drive shaft (5), the wire guide disk further having a wire guide disk cover (7) connected to the drive shaft (5), a wire guide disk cover heater (8) surrounded by the wire guide disk cover (7) and at least one cooler, characterized in that at least a part of the wire guide disk drive motor (2) and the motor support (4) and at least one flow channel of the cooler are arranged in a part (C) of the wire guide disk (1) surrounded by the wire guide disk cover (7) and that part (C) of the wire guide disk cover (8) is also provided with the heater.

2. A godet according to claim 1, characterized in that at least a part of the godet drive motor (2) and the motor support (4) are arranged in an inner cavity of a carrier (9) and that the at least one flow channel extends through the material of the carrier (9) between the godet drive motor (2) and the godet cover heater (8).

3. A guidewire disc according to claim 2, characterized in that the cooler has a coil with an inlet (31) and a return (32) for the cooling fluid arranged side by side.

4. A godet according to claim 3, characterized in that the inlet opening (31) and the return opening (32) are located in the material and/or on the inner wall of the carrier (9) on the same diameter, and/or the inlet opening (31) and the return opening (32) are located in the material and/or on the inner wall of the carrier (9) on mutually offset diameter steps, and/or the inlet opening (31) and the return opening (32) are located in a conical converging or diverging manner in the material and/or on the inner wall of the carrier (9).

5. A godet according to claim 4, characterized in that the coiled tube is a steel tube poured into the material of the carrier (9).

6. A wire guide disc according to claim 3, characterized in that at least one further coil extends in the material of the carrier (9) and/or on the inner wall parallel to the coils of the cooler, in which at least one further coil a further medium different from the cooling fluid is guided.

7. A guidewire disc according to claim 2 or 4, characterized in that the carrier (9) is composed of a metallic material and/or a mineral material.

8. A godet according to claim 2 or 4, characterized in that the carrier (9) has a carrier insert (91) embedded in the portion (B) of the godet (1) surrounded by the godet cover (7) and a carrier sleeve (92) on which the godet cover (7) is seated.

9. A godet according to claim 8, characterized in that a distance is created between the godet cover heater (8) and the carrier (9) by means of at least one spacer (15, 16), in which distance air (14) is located.

10. A wire guide disc according to claim 2 or 4, characterized in that on the drive shaft (5) a fan wheel (12) rotating with the drive shaft (5) is arranged in the carrier (9).