EP1614783B1 - Inductor core for a heatable galette - Google Patents

Description

The invention relates to an inductor core for an inductively heated godet and an inductor and an inductively heated godet. The inductor core comprises a plurality of star-shaped radially arranged Induktorkernlamellen with radial sections and in each case an outer and an inner axial section. In the inductor, a sleeve is disposed around the inductor core laminations with the outer axial portions of the inductor core laminations adjacent the sleeve. Such godets are used on spinning machines or on machines for producing fibers, for example yarns, as guide and take-off rolls for the fibers to be processed.

Inductively heated godets are known in the art. Such godets have a magnetic inductor core, which is wound with coil windings, wherein the coil windings can be acted upon by an electrical alternating current. The coil windings, together with the inductor core, form an inductor which enables inductive heating of the godet. The inductor core causes bundling and amplification of the magnetic field generated by the current-carrying coil windings. By induced by the inductor magnetic field electrical eddy currents are induced in electrically conductive parts of the galette, which heat the electrically conductive parts and thus the galette.

There are known inductor cores made of gray cast iron. Although gray iron inductor cores can be produced inexpensively, even at low magnetic field strengths, ie at approximately 1100 VA, the inductor cores become magnetically saturated, which impedes penetration of the magnetic field generated by the electrical current flowing in the coil windings into the inductor core. High heating capacities that make it possible to heat the surfaces of the godet in contact with the fibers to be processed to a temperature of 240 ° C. and above, which is necessary for various processing methods of fibers, are therefore difficult to achieve with gray iron inductor cores. In addition, electrical eddy currents are also induced in such inductor cores. This leads to a heating of the inductor core itself, which makes a rapid control of the galette temperature difficult.

With a power consumption of the galette of 1100 VA, temperatures of 240 ° C can be reached, but only at low rotation speeds of the godet. Most of the power is applied to compensate for heat losses of the rapidly rotating galette to the environment. With increasing rotational speed, this heat loss increases quadratically. 1100 VA represents a performance limit for a size galette of 90 mm length and 100 mm diameter. Larger godets also allow higher heat outputs with a cast iron inductor core. However, enlarging the godet leads to a larger godet surface, which increases the proportion of heating energy that is proportional to this surface. As a result, a large proportion of the heating power gained by enlarging the godet is compensated.

Furthermore, inductors with laminated inductor cores are known. In such inductor cores, inductor core laminations having radial sections and each having an outer and an inner axial section are arranged around an inner tube such that the inductor core laminations each adjoin the outer surface of the inner tube with their inner axial section. The Induktorkernlamellen are welded to the inner axial portion of each of the outer surface of the inner tube. The Induktorkernlamellen are made of transformer sheet. The inductor core is wound with coil windings. When wrapping care must be taken that insulation of the wire from which the coil windings are constructed is not damaged. Laminated inductor cores prevent, according to a laminated Transformer core, the formation of eddy currents in the inductor core. If the sleeve is made of an electrically conductive material, eg of steel, eddy currents are induced in the sleeve which lead to a heating of the sleeve and thus of the godet, into which the inductor core is inserted. The inductor core itself does not heat up significantly by laminating the inductor core. Local heating is achieved close to the surface of the galette. Laminated inductor cores have significantly higher magnetic saturation limits than gray iron inductor cores due to the material used to make the fins, which allows much higher magnetic fields to be generated by the inductors. A disadvantage of the known laminated inductor cores is that the Induktorkernlamellen must be individually welded to the inner tube. Furthermore, it is complicated to arrange the inductor core lamellae in a star shape, ie spaced apart from one another at the outer diameter. The sheets from which the Induktorkernlamellen are made, they are provided at their outer areas with a nose as a spacer. When assembling the Induktorkerns the sheets are then arranged individually. For better fixation, the sheets can be fixed to a sleeve with a weld seam, whereby disadvantageous eddy currents occur during operation of a galette equipped with such an inductor core.

Although high heating capacities can be achieved with laminated inductor cores, they are complicated to manufacture and therefore cost-intensive.

The pamphlets DE 19 57 110 A1 and CH 467 363 A each disclose a heatable Gallette with an inductor core, which comprises a plurality of star-shaped radially arranged Induktorkernlamellen, wherein formed as locking fixation means are provided. The latches are formed circumferentially on Abschlußdorfer so that the Induktorkernlamellen are secured against slipping in the radial direction.

The publication US 3,448,233 discloses a heatable Gallette with an inductor core, which has a plurality of star-shaped radially arranged Induktorkernlamellen, which are formed as cuboid packets of sheets.

The invention has for its object to provide an inductor core and an inductor for an inductively heated godet and an inductively heated godet, which avoid the disadvantages of the prior art and in particular are easy to manufacture and allow high heat output.

This object is achieved by the inductor core according to claim 1, the inductor according to claim 9 and the godet according to claim 10. The dependent claims represent preferred embodiments of the invention.

The task with respect to the inductor core is achieved by an inductor core for a heatable godet with a plurality of star-shaped radially arranged inductor core lamellae with radial sections and in each case one outer and one inner axial section. The inductor core has fixing means designed as latches, wherein the fixing means are arranged to fix the inductor core lamellae at their radial sections to termination plates each having a surface complementary to the radial sections. The inductor core laminations are arranged between the finalists. The locking means formed as locking means are formed as radially outwardly extending arranged on the Abschlußstellern and at the radial sections of tongue and groove locks. The latches are designed according to tongue and groove connections, wherein preferably the radial sections of the inductor core lamellae are inserted as a spring into mating complementary grooves in the termination plates, that is to say latched. This is a particularly easy to manufacture embodiment of the fixative.

In addition, the fixing means may be arranged to lock the Induktorkernlamellen with their inner axial sections on an outer surface of an inner tube with the inner tube. The inductor core therefore has termination plates each with a surface that is complementary to the radial sections. The Induktorkernlamellen are arranged between the Abschlußstellern and the fixing means are adapted to fix the Induktorkernlamellen at the radial portions of the Abschlußstellern. The complementary surfaces of the terminator points in the direction of the radial sections of the Induktorkernlamellen. The surfaces have a shape that shapes the radial sections. In the simplest case, the radial sections and / or the axial sections are straight edges of, preferably punched, sheets. The impressions on the surfaces of the end plates are designed as grooves that extend radially outward from a center point of the respective plate and into which in each case a radial section of the inductor core lamellae can be inserted. This leads to a positional fixation of the inductor core laminations relative to the termination plates.

No welding operations are necessary for the production of the inductor core according to the invention. The Induktorkernlamellen be through easy assembly and / or mating fixed to the end plates or the inner tube. A laminated inductor core is provided which combines the advantages of known laminated inductor cores with a simple and inexpensive manufacturability. With the inductor core according to the invention heating powers of 1000 watts and more can be achieved, whereby the coming into contact with the fibers in contact surfaces of a galette can be heated above 240 ° C. It is a precise heating with rapid temperature changes possible. Furthermore, a change in the inductor core length is very easily possible by varying the length of the inductor core lamellae, without incurring additional expense during assembly of the inductor core.

Particularly preferably, the inductor core lamellae are formed as cuboidal packets of sheets, preferably with integrally formed spacers. As in the case of transformers, cuboidal laminations can be produced very cheaply from punched sheet metal parts. The arrangement of a plurality of cuboid laminated cores facilitates the assembly of the inductor core according to the invention over an embodiment with many individual sheets as Induktorkernlamellen, wherein the magnetic properties may have the same values. The spacers prevent that the sheets can be electrically conductively connected over a large area, whereby the formation of eddy currents is further complicated. In addition, a regular distance between the sheets is achieved, creating a symmetrical magnetic field and thus a uniform heating of the godet can be achieved.

The sheets are preferably formed as stampings. This allows a simple and rapid production of Induktorkernlamellen. The Induktorkernlamellen can preferably be made of transformer sheet, for example punched.

The catches particularly preferably each comprise a peripheral groove in the end plates and complementary elevations on the radial sections and radial grooves complementary to the radial sections in the end plates. This embodiment of the latches is particularly suitable for the positional fixing of inductor core lamellae designed as a package of sheets. The packets are thereby prevented by the circumferential groove from slipping in the radial direction and by the radial groove from slipping and / or twisting perpendicular to the radial direction.

Particularly advantageously, the Induktorkernlamellen on their outer axial sections led out radial section extensions of the radial sections. This shape of the inductor core lamellae enables effective removal of the magnetic field from the region of the inductor core into electrically conductive parts of the godet. These parts can be heated up very quickly and effectively. In addition, a position fixation of a sleeve provided with coil windings on the Induktorkernlamellen may result.

The terminators are preferably screwed together with axially extending, preferably in intermediate spaces between the Induktorkernlamellen, screws. Such screwing allows a stable fixation of the inductor core lamellae in the axial direction of the inductor core. The terminators and the inductor core lamellae are held together axially. The screws themselves additionally amplify a generated magnetic field when passed between the inductor core laminations.

The terminators are preferably made of non-magnetic material, e.g. made of aluminum. A field gain in the axial direction out of the region of the inductor core is thereby avoided. An inductor according to the invention comprises, in addition to an inductor core according to the invention, coil windings, wherein the coil windings are wound onto the inductor core. The coil windings can also be wound onto a sleeve enclosing the inductor core. The bobbin, i. the coil windings on the sleeve, can then be prefabricated. In this case, the Induktorkern can be inserted into the bobbin or the Induktorkernlamellen are individually inserted into the sleeve for mounting the inductor and subsequently the end plates are added, wherein the fixing means, i. Preferably, the locking, be positioned appropriately and optionally subsequently the inductor core is screwed axially.

A heatable godet according to the invention has a cylindrical basic shape, wherein an inductor according to the invention is arranged in the godet.

• Figur 1 zeigt einen erfindungsgemäßen Induktorkern, wobei ein Abschlussteller zur Illustration der komplementären Oberfläche und damit der Fixierungsmittel in Figur 1a weggeklappt dargestellt ist.
• Figur 2 zeigt eine bevorzugte Ausführungsform eines erfindungsgemäßen Induktorkerns mit als quaderförmige Pakete aus Blechen ausgebildeten Induktorkernlamellen.
• Figur 3 zeigt eine als ein Paket von Blechen ausgebildete Induktorkernlamelle, wie diese zum Aufbau eines Induktorkerns gemäß der Darstellung in Figur 2 verwendet ist.
• Figur 4 zeigt eine erfindungsgemäße induktiv beheizbare Galette im Querschnitt.

The invention will be explained in more detail by means of embodiments with reference to the drawings.

• FIG. 1 shows an inductor core according to the invention, wherein a termination plate for illustration of the complementary surface and thus of the fixing means is shown folded away in FIG. 1a.
• FIG. 2 shows a preferred embodiment of an inductor core according to the invention with inductor core laminations designed as cuboidal packets of sheet metal.
• FIG. 3 shows an inductor core lamination formed as a package of laminations, as used to construct an inductor core as shown in FIG.
• FIG. 4 shows an inductively heatable godet according to the invention in cross section.

The figures of the drawings show the subject matter of the invention in a highly schematic manner and are not to scale. The individual components of the article according to the invention are shown so that their structure can be well shown.

FIG. 1 shows an inductor core 10 according to the invention. The inductor core 10 has a plurality of star-shaped radially arranged inductor core fins 11 with radial sections 12 and in each case an outer axial section 13 and an inner axial section. The inductor core 10 comprises two termination plates 19, 20, preferably made of a non-magnetic material, eg aluminum, each having a surface 21 complementary to the radial sections 12 and fixing means 22. The inductor core lamellae 11 are arranged between the termination plates 19, 20. The fixing means 22 are arranged, the Induktorkernlamellen 11 at the radial portions 12th to fix the termination plates 19, 20. The Induktorkernlamellen 11 have on the outer axial sections 13 led out Radialabschnittsverlängerungen 14 of the radial sections 12. An end plate 19 is shown folded away to illustrate the complementary surface 21 and thus the fixing means 22 in Figure 1a. The fixing means 22 are formed as arranged radially on the Abschlußstellern 19, 20 and the radial portions 12 notches 23. The latches are formed from the regions of the inductor core lamellae 11 adjoining the radial sections 12 and radial grooves 28 in the termination plates 19, 20. In the simplest case, the radial grooves 28 are slots in the termination plates 19, 20 which correspond in length and width to the radial sections 12 of the inductor core lamellae 11. The inductor core fins 11 are arranged around an inner pipe 25 such that the inner axial portions of the inductor core fins 11 adjoin the inner pipe 25.

Slipping of the Induktorkernlamellen in the radial direction inward is prevented. However, it is also possible to dispense with an inner tube since the Induktorkernlamellen can be fixed in position in the radial direction by appropriate design of the fixing means to the Abschlusstellern 19, 20.

FIG. 2 shows a preferred embodiment of an inductor core according to the invention with inductor core lamellae 11 formed as plates which are substantially cuboid-shaped packets 31. For example, eight packets 31, are provided for the radial grooves 28 in the Abschlusstellern 19, 20, arranged in a star shape. The Induktorkernlamellen 11, including the individual sheets from which the Induktorkernlamellen are joined together, have over the outer axial sections 13 led out Radialabschnittsverlängerungen 14 of the radial sections 12. The latches are each a circumferential groove 26 for radially fixing the Induktorkernlamellen 11 in the Abschlusstellern 19, 20 and complementary elevations 27 on the radial sections 12 of the Induktorkernlamellen 11, and to the radial sections 12 of the Induktorkernlamellen 11 complementary radial grooves 28 in the Abschlusstellern 19th , 20 trained. The termination plates 19, 20 are screwed together with axially extending, guided in intermediate spaces between the Induktorkernlamellen 11 screws 30. The sheets from which the Induktorkernlamellen are assembled, may be formed as stamped parts. The individual sheets may also be insulated from each other with an electrically insulating layer.

In FIG. 3, one is shown as a package 31 of inductor core laminations 11 as used to construct an inductor core as shown in FIG. The package 31 comprises six sheets. The individual inductor core lamella 11 has a radial section 12, wherein a radial section extension 14 is led out beyond the outer axial section 13 of the inductor core lamella 11. At the radial sections 12, in the region of the radial section extension 14, the inductor core lamella 11 has elevations 27. These elevations 27 are suitable, as a package 31 of Induktorkernlamellen 11, as shown in Figure 2, according to a tongue and groove connection, in circumferential grooves in the surfaces of Abschlusstellern to lock with the Abschlusstellern. The individual sheets of the package 31 have one of the described form of Induktorkernlamelle 11 corresponding shape.

FIG. 4 shows an inductively heatable godet according to the invention in cross-section, with only an upper half of the godet being illustrated above the axis of rotation of the godet. The inductor core 10, the coil windings 32, the godet casing 37 of the cylinder forming the basic shape of the godet, and the termination plates 19, 20 are shown. The godet casing 37 forms a short-circuit ring for the magnetic field lines 34 of the magnetic field induced by the inductor core 10. About an example copper ring 33, the induced current is amplified.

The invention is not limited to the embodiments given above. Rather, a number of variants are conceivable, which make use of the features of the invention even with fundamentally different type of execution.

Proposed is an inductor core 10 for a heated godet with a plurality of star-shaped radially arranged Induktorkernlamellen 11 with radial sections 12 and each having an outer axial section 13 and an inner axial section.

The inductor core 10 has termination plates 19, 20 each with a surface 21 complementary to the radial sections 12 and fixing means 22, wherein the inductor core lamellae 11 are arranged between the termination plates 19, 20 and wherein the fixing means 22 are arranged are to fix the Induktorkernlamellen 11 at the radial portions 12 to the Abschlusstellern 19, 20 or alternatively and / or on the outer surface of an inner tube.

Claims (10)

1. An inductor core (10) for a heatable godet roll (35) comprising a plurality of inductor core laminations (11) arranged radially in a star shape with radial sections (12) and respectively one outer axial section (13) and one inner axial section, wherein the inductor core (10) has fixing means (22) embodied as locating devices (23), wherein the fixing means (22) are set up to fix the inductor core laminations (11) at their radial sections (12) on end plates (19, 20) with respectively one surface (21) complementary to the radial sections (12) so that the inductor core laminations (11) are arranged between the end plates (19, 20), characterized in that the locating devices (23) are embodied as tongue-and-groove locating means (23) which are arranged on the end plates and on the radial sections and extend radially outward.
2. The inductor core for a heatable godet roll (35) according to claim 1, characterised in that the inductor core laminations (11) are constructed as almost rectangular packages (31) of sheet metal.
3. The inductor core for a heatable godet roll (35) according to claim 2, characterised in that the metal sheets are embodied as stamped parts.
4. The inductor core (10) for a heatable godet roll (35) according to at least one of claims 1 to 3, characterised in that the fixing means (22) are set up to locate the inner axial sections of the inductor core laminations (11) on an outer surface of an inner tube.
5. The inductor core for a heatable godet roll (35) according to at least one of the claims 1 to 4, characterised in that the locating means each comprise one circumferential groove (26) in the end plates (19, 20) and elevations (27) complementary thereto on the radial sections (12) and radial grooves (28) complementary to the radial sections (12) in the end plates (19, 20).
6. The inductor core for a heatable godet roll (35) according to at least one of claims 1 to 5, characterised in that the inductor core laminations (11) have radial-section extensions (14) of the radial sections (12) which extend over their outer axial sections (13).
7. The inductor core for a heatable godet roll (35) according to at least one of claims 1 to 6, characterised in that the end plates (19, 20) are screwed together using screws (30) running axially, preferably guided in intermediate spaces between the inductor core laminations (11).
8. The inductor core for a heatable godet roll (35) according to at least one of claims 1 to 7, characterised in that the end plates (19, 20) are made of a non-magnetic material, preferably of aluminium.
9. An inductor for a heatable godet roll (35) comprising an inductor core (10) according to at least one of claims 1 to 8, and coil windings (32) wherein the coil windings (32) are wound around the inductor core laminations (11).
10. A heatable godet roll (35) comprising a cylindrical basic shape and an inductor according to claim 9 arranged in the godet roll (35).

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