WO2002012603A2 - Galette unit - Google Patents

Abstract

The invention relates to a galette unit for conveying and guiding at least one running synthetic thread. A pot-shaped galette cover is mounted on a support in such a way that it protrudes, by means of a drive shaft with at least one rolling bearing. Said drive shaft is connected to an electric drive. According to the invention, a means of cooling the inner ring of the rolling bearing mounted on the drive shaft is provided in order to prevent the rolling bearing from being heated through the drive shaft, ensuring a homogenisation and maintenance of the operating temperatures between the outer ring and the inner ring in the rolling bearing.

Description

 galette

The invention relates to a godet unit for conveying and guiding a running thread according to the preamble of claim 1.

Such godet units are known for guiding individual threads or groups of threads in spinning systems and. promote, for example, to withdraw the thread or threads from a spinneret or, for example, to stretch the thread or threads. Here, the godets are generally equipped with a single drive, which drives the drive shaft connected to a godet jacket. The drive shaft is usually mounted in an area between the godet casing and the electric drive, as is known, for example, from DE 37 01 077.

Due to the high thread speeds of well over 1,000 m / min that are common today, very high drive speeds are achieved. In addition to the heating of the bearing caused by the bearing friction, these high loads also lead to a relatively high thermal energy in the electric drive. The problem arises here that a substantial proportion of the thermal energy of the electric drive is introduced into the bearings via the drive shaft. This phenomenon leads to an undesired temperature difference in the roller bearings, so that the inner ring of the roller bearing connected to the drive shaft has a higher temperature than the outer ring of the roller bearing supported on a carrier. This results in an undesirable fluctuation in the bearing preload. This problem is even more evident in godet units in which the godet jacket is heated, since the thermal energy transmitted by the drive shaft increases significantly. In the known godet, the bearing bore is made directly in the machine wall of the machine frame designed as a housing. However, this arrangement is not suitable to prevent the roller bearings from overheating.

A further godet unit is known from US Pat. No. 4,822,972, in which the drive shaft is mounted in a carrier via at least one roller bearing. The carrier has a plurality of cooling channels, which in particular cool the outer region of the rolling bearing. Such a design essentially absorbs and dissipates the heat given off by the outer ring of the roller bearing on the carrier by the cooling medium. However, this only increases the problem of differential temperatures between the inner ring and the outer ring of the rolling bearing.

It is therefore an object of the invention to design a godet unit for conveying and guiding at least one running thread of the type mentioned at the beginning with a bearing cooling which on the one hand prevents overheating and on the other hand leads to a non-uniformization of the operating temperatures within the rolling bearing.

The solution to the problem results from the features of claim 1.

Further advantageous developments of the invention are defined in the subclaims.

During the operation of a godet unit, the bearing shaft of the drive shaft is essentially heated on the one hand by the bearing friction within the rolling bearing and on the other hand by the amount of heat supplied from the outside. The heat generated by the bearing friction reaches the inner ring and the outer ring of the rolling bearing evenly or unevenly, depending on the design conditions. The heat supplied from outside reaches the rolling bearing depending on the place of origin and the heat conduction within the godet unit. It is known that the electric drive of the drive shaft leads directly to heating of the drive shaft. The heat dissipation from the drive shaft is now preferably provide clock to the con-, so that in particular an additional ^'amount of heat is conducted in-the inner ring of the bearing. The invention now has the advantage that an amount of heat introduced via the drive shaft cannot affect the operating temperature of the rolling bearing. For this purpose, the godet unit has a means for directly cooling the inner ring. This essentially maintains a uniform operating temperature between the outer ring and the inner ring of the rolling bearing. The influence of external heating is essentially kept away from the rolling bearing, so that a very precise design of the rolling bearing is possible.

The means for cooling the inner ring can be designed particularly advantageously as a heat sink which is in heat-transferring contact with the inner ring of the rolling bearing. For this purpose, the heat sink is arranged next to the roller bearing and extends at least radially over a partial circumference of the inner ring. This enables a uniform and continuous heat transfer and heat dissipation.

In order to simultaneously absorb and dissipate a portion of the heat contained in the drive shaft, the heat sink is preferably designed as an annular cooling ring which is attached to the circumference of the drive shaft next to and / or below the inner ring.

In another particularly advantageous embodiment of the heat sink, it is formed in two parts from a cooling ring and a cooling fin carrier. The cooling ring is attached to the circumference of the drive shaft and is connected in such a heat-transferring manner to the cooling fin carrier attached to the carrier that the cooling ring can rotate with the drive shaft relative to the cooling fin carrier. The special The advantage of this further development lies in the fact that the heat-emitting surfaces of the heat sink are thus significantly enlarged and a relatively high heat dissipation is possible.

For heat transfer between the rotating cooling ring and the stationary cooling fin carrier, several excellent cooling webs are advantageously attached to the cooling ring and the cooling fin carrier in such a way that they overlap one another without obstructing the rotary movement. This creates the largest possible transfer areas.

In order to enlarge the heat-emitting surface of the heat sink on the circumference, the heat sink is advantageously designed with cooling fins.

Particularly in the case of the cooling fins attached to the circumference of the cooling ring, cutouts in the cooling fins result in a turbulent cooling air flow which is advantageous for cooling being generated when the cooling ring rotates with the drive shaft.

The design of the bearing cooling according to the invention is not only limited to godet units with one bearing. On the contrary, in particular in the case of mounted drive shafts in which two roller bearings with axial preload are provided, the coolant assigned to the roller bearings can achieve a relatively high constancy of the preload force. The disadvantage that temperature differences between the inner ring and the outer ring of the rolling bearing causes a change in the angular position and thus the preload force in the case of inclined rolling bearings can be avoided. In this respect, the direct heat dissipation on the inner ring of the rolling bearing prevents a change in the angular position, so that the axial preload remains essentially unchanged. In order to prevent the cooling of the rolling bearings from influencing each other, the cooling bodies are preferably mounted on the sides of the inner rings facing outside the bearing bore, preferably on the side of the rolling contact between the rolling body and the inner ring.

In particular, the heat sink facing the drive side can advantageously be flushed with a cooling fluid, preferably with a cooling air that is generated by a cooling fluid generator on the drive side. Cooling fluid generators of this type are primarily used for cooling the electric drive. However, the cooling air or a cooling fluid can also advantageously be conducted via cooling channels to the cooling body attached to the projecting side of the godet unit.

The godet unit according to the invention is particularly suitable for heating the threads guided on the godet jacket. For this purpose, a heating means is provided for heating the godet casing, which is arranged in an annular space formed between the godet casing and the drive shaft. The heat dissipated inwards to the drive shaft is advantageously absorbed and emitted via the heat sinks directly on the inner ring of the roller bearings.

Further advantages and features of the invention will now be explained in more detail using some exemplary embodiments with reference to the accompanying drawings.

Show it:

1 schematically shows a longitudinal section through a first exemplary embodiment of the godet unit according to the invention;

2 schematically shows a longitudinal section through an embodiment of a heated godet unit. . In Fig. 1, a longitudinal section through a godet unit according to the invention is shown schematically. The godet unit consists of a godet jacket 2. The godet jacket 2 is pot-shaped and placed over a drive shaft 1. The projecting end of the drive shaft 1 is rotatably connected to an end wall 4 of the godet casing 2. The godet casing 2 is held on the drive shaft 1 via the bracing element 5. At the opposite end of the drive shaft 1, the drive shaft 1 is coupled to a drive 3. The drive 3 is designed as an electric motor and drives the drive shaft 1 and thus the godet casing 2.

In the area between the godet casing 2 and the drive 3, the drive shaft is supported by two roller bearings 6.1 and 6.2 arranged at a distance from one another. For this purpose, a bearing bore 11 is made in a carrier 10 penetrated by the drive shaft 1, in which the roller bearings 6.1 and 6.2 are received. The roller bearings 6.1 and 6.2 each have an inner ring 8, a rolling element 9 and an outer ring 7. The roller bearings 6.1 and 6.2 are fitted in the bearing bores 11 in such a way that the outer rings 7.1 and 7.2 are held in the carrier 10 and the inner rings 8.1 and 8.2 sit on the drive shaft 1. The bearing bores 11 are connected via an essentially concentric shaft bore made in the carrier 10. The shaft bore is dimensioned such that an air gap forms between the carrier 10 and the drive shaft 11.

To cool the bearings, a cooling body 12.1 and 12.2 is assigned to each rolling bearing 6.1 and 6.2 as a coolant. The heat sink 12.1 is formed by a cooling ring 13.1, which is attached directly next to the inner ring 8.1 of the rolling bearing 6.1 on the circumference of the drive shaft 1. The cooling ring 13.1 and the inner ring 8.1 are in heat-conducting contact. For this purpose, the cooling ring 13.1 is arranged directly on the side of the roller bearing 6.1 facing the projecting end of the drive shaft 1. The cooling ring 13.1 has a heat-emitting opposite to its contact surface resting on the inner ring 8.1 Cooling surface. To enlarge the cooling surface, a plurality of cooling ribs 14 are formed on the cooling ring 13.1 in such a way that they extend in the axial direction and surround the drive shaft 1 as rings with different diameters lying concentrically radially one behind the other.

The heat sink 12.2 is assigned to the rolling bearing 6.2 facing the drive side. Here, the heat sink is also designed as a cooling ring 13.2, which bears with a contact surface on the inner ring 8.2 and is attached to the circumference of the drive shaft. In this case, the peripheral surface of the cooling ring 13.2 is designed as a cooling surface with a plurality of cooling fins 14.2. The cooling fins are axially formed on the circumference of the cooling ring 13.2 in a disk-like manner. The cooling fins 14.2 and part of the cooling ring 13.2 protrude outside the bearing bore 11 of the carrier 10 into the interior of the housing 15 slipped over the drive 3. The housing 15 is attached to the carrier 10 and encloses the drive 3. The housing 17 has on the closed end face, an opening through which the power supply to the drive 3 takes place via the line 16.

In the embodiment of the godet unit according to the invention shown in FIG. 1, the drive shaft 1 is driven to rotate by the drive 3, in particular an electric motor. With the drive shaft 1, the godet casing 2 rotates to guide one or more threads that lie against the circumference of the godet casing. The cooling rings rotate in the bearing area of the drive shaft 1

13.1 and 13.2 and the inner rings 8.1 and 8.2 of the roller bearings 6.1 and 6.2 with the drive shaft 1. The heat introduced by the drive 3 into the drive shaft 1 is directly from the drive shaft 1 into the cooling ring 13.1 and

13.2 and transferred to the inner rings 8.1 and 8.2. Compared to the inner ring 8 of the rolling bearing 6, the Kü lring is made of a material which is particularly characterized by a high thermal conductivity, such as aluminum or aluminum alloys. The cooling ring 8 is therefore particularly well suited for the transport of thermal energy. Due to the molded cooling rib The amount of heat introduced into the cooling ring is released into the environment. This results in a heat transfer from the inner ring 8 at the contact surface of the cooling ring, so that the amount of heat introduced into the bearing ring by the drive shaft 1 is emitted directly to the cooling ring 13. The cooling of the inner rings 8.1 and 8.2 thus prevents a significant temperature difference between the outer ring 7 and the inner ring 8 of the roller bearings 6 from occurring. An operating temperature prevailing in the rolling bearing essentially depends on the bearing friction and the bearing forces.

The design of the heat sinks 12.1 and 12.2 for cooling the inner rings 8 of the roller bearings 6 is exemplary. Any other shape that makes contact with the inner ring 8 of the roller bearing 6 can be carried out. It is essential for the godet unit according to the invention that the heat introduced into the roller bearing from the outside can be dissipated directly in order to avoid possible temperature differences in the roller bearing.

An exemplary embodiment of a heated godet unit is shown in FIG. The components with the same function were given identical reference numbers. The arrangement of the godet casing 2, the drive shaft 1, the drive 3, the carrier 10 and the housing 15 is essentially identical to the exemplary embodiment shown in FIG. 1. To avoid repetition, reference is made to the description of FIG. 1.

In the exemplary embodiment in FIG. 2, a hollow cylindrical heating support 17 is placed over the drive shaft 1 in the area within the godet casing 2 and attached to the support 10 with one end face. A heating means 18 extending essentially over the length of the godet casing 2 is arranged on the circumference of the heating support 17. The heating means 18 is preferably formed by electrical coils, which enable the godet casing 2 to be heated by induction. The drive shaft 1 is supported by the roller bearings 6.1 and 6.2 in the carrier 10. Each of the roller bearings 6.1 and 6.2 is assigned a heat sink as a coolant. The inner ring 8.1 of the roller bearing 6.1 is cooled by the cooling ring 13.1, which is constructed identically to the previous embodiment according to FIG. 1.

In contrast, the roller bearing 6.2 is assigned a heat sink, which consists of a cooling ring 20 and a cooling fin carrier 22. The cooling ring 20 is mounted on the side of the roller bearing 6.2 facing the drive on the circumference of the drive shaft 1 such that an end face of the cooling ring 20 is in contact with the inner ring 8.2 of the roller bearing 6.2. On the opposite end face of the cooling ring 20, a plurality of cooling webs 21 formed in the axial direction are formed by annular incisions in the end face of the cooling ring 20. The cooling fin carrier 22 is fastened to the carrier 10. Here, the cooling fin carrier has congruent cooling webs 23 at the level of the incisions of the cooling ring 20, which protrude into the incisions of the cooling ring 20, so that the cooling webs 21 of the cooling ring 20 and the cooling webs 23 of the cooling fin carrier 22 overlap without contact. A thermal bridge is thus formed between the cooling ring 20 and the cooling fin carrier 22, which does not hinder the rotational movement of the drive shaft 1. The cooling fin carrier 22 has a plurality of axially directed cooling fins 14 on the end face facing away from the carrier. The cooling fins are ring-shaped or segment-shaped in order to realize the largest possible cooling surface on the cooling fin carrier 22.

Within the housing 15, a cooling fluid generator 19 is coupled to the electric motor 3, so that a cooling air flow can be generated, which flows around both the drive 3 and the cooling body 12.2.

In order to improve the cooling effect of the cooling ring 13 on the opposite side of the carrier 10, a cooling air flow into the area of the godet casing can be made by appropriate air channels in the housing 15 and / or the carrier 10 lead to intensify the cooling of the rolling bearing 6.1 in cooperation with the cooling ring 13. The design of the heat sink in the exemplary embodiment shown is also exemplary.

The invention is not limited to the fact that the inner ring of the rolling bearing is cooled by a cooling body in contact with the inner ring. Solutions are also shown, in which a cooling medium, for example a heat transfer fluid, is guided directly in the vicinity or through the inner ring of the rolling bearing. The heat sink is replaced by a heat conduction system.

When using heat sinks there is basically also the possibility that the contact area between the roller bearing and the heat sink is not limited to the inner ring of the roller bearing. An expansion of the contact surface at least to a partial area of the outer ring of the rolling bearing is possible without major problems. Thus, on the one hand, larger differential temperatures between the inner ring and the outer ring, but on the other hand, an overall reduction in the operating temperature of the rolling bearing can be achieved. In the event that the heat energy introduced from the outside into the roller bearing is essentially transmitted from the carrier 10 and not from the drive shaft 1, a change can also be carried out in such a way that the heat sink essentially only in heat-conducting contact with the outer ring of the roller bearing stands.

LIST OF REFERENCE NUMBERS

drive shaft

godet

drive

bulkhead

bracing

Rolling bearing ^: outer ring

inner ring

Rolling element carrier

bearing bore

heatsink

Cooling ring cooling fins

Housing line heating element

Heating medium cooling fluid generator cooling ring

cool bar

Fins carrier

cool bar

Claims

claims 1. godet unit for guiding and conveying a running thread with a rotationally driven drive shaft (1), which rotatably with a cup-shaped godet jacket (2) and with an electric Drive (3) is connected and which is supported by at least one roller bearing (6) projecting on a carrier (10), the roller bearing (6) having an outer ring (7) on the carrier (10) and an inner ring (8 ) on the drive shaft (1), characterized in that a means (12) for cooling the inner ring (8) is provided in order to bring about an equalization and maintenance of the operating temperatures of the outer ring (7) and the inner ring (8) in the roller bearing , 2. godet unit according to claim 1, characterized in that the means is designed as a heat sink (12) which is in heat-transferring contact with the inner ring (8) of the rolling bearing (6) and which is at least over a partial circumference of the L nenringes (8 ) extends. 3. godet unit according to claim 2, characterized in that the cooling body (12) is designed as an annular cooling ring (13) and is attached to the circumference of the drive shaft (1) next to the inner ring (8). 4. godet unit according to claim 2 or 3, characterized in that the cooling body (12) on the drive shaft (1) attached, cooling ring (20) and with the carrier (10) connected to the cooling rib carrier (22) and that Cooling ring (20) and the cooling rib Pen carrier (22) are connected to each other in such a heat-transferring manner that the cooling ring (20) rotates relative to the cooling fin carrier (22) with the drive shaft (1). 5. godet unit according to claim 4, characterized in that the cooling ring (20) and the cooling fin support (22) each have a plurality of excellent cooling webs (21, 23) which overlap each other for heat transfer without contact. 6. godet unit according to one of claims 2 to 5, characterized in that the cooling body (12) in a region outside of a bearing bore (11) introduced in the support bore (11) has a plurality of cooling fins (14). 7. godet unit according to claim 6, characterized in that the cooling fins (14) on the circumference of the heat sink (12) are axially directed and / or radially directed. 8. godet unit according to claim 6 or 7, characterized in that the cooling fins (14) on the circumference of the cooling ring (13) have several recesses for influencing a cooling air flow. 9. godet unit according to one of claims 1 to 8, characterized in that a second roller bearing (6.2) is provided for mounting the drive shaft (1), which is arranged at a distance from the first roller bearing (6.1), and that each roller bearing ( 6.1, 6.2) a means for cooling (12.1, 12.2) of the inner rings (8.1, 8.2) is assigned. 10. godet unit according to claim 9, characterized in that each inner ring (8.1, 8.2) on the outside facing the bearing bore (11) facing sides with a heat sink (12.1, 12.2) is in heat-transferring contact. 11. godet unit according to one of claims 2 to 10, characterized in that a cooling fluid generator (19) is provided on the drive side for generating a cooling fluid, which cooperates with at least one heat sink (12) for cooling the associated inner ring (8). 12. godet unit according to one of the preceding claims, characterized in that a heating means (18) for heating the godet casing (2) is provided, which in a between the godet casing (2) and the drive shaft (1) formed annular space is arranged.