Godet For Drawing Units And Roller Dryers Used For Treating Man-made Fibers

Abstract

The present invention is directed to a godet for installation in drawing units and roller dryers used for treating natural and synthetic fibers, which comprises an outer and inner cylindrical jacket provided with a front wall, said outer and inner jacket defining a channel therebetween, means for introducing a forced flow of a heat transfer medium to the annular channel for heating the godet, and a bearing shaft means attached to the front wall of the godet by radial and axial fittings and fixedly but rotatably mounted in bearing boxes associated therewith, the metal contact surfaces of the fitting areas between the bearing shaft and the front wall of the godet being discontinuous.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a godet for installation in drawing units and roller dryers which are preferably used for treating man-made fibers. The godet features two concentric cylinders which provide a double jacket and the forced flow of a heat carrier for heating the godet in the annular clearance between the two cylinders, (see U.S. Pat. No. 3,581,812, granted June 1, 1971). The bearing shaft of the godet is fastened to a front wall by radial and axial fittings and supported in a fixed position but pivoting in the respective bearing box.

The treatment of textile materials of any kind on heated cylinders for the purpose of drawing or drying the individual fibers also serves for applying chemical finishes to the fibers. While drawing and squeezing the material it is also intended to improve the distribution of pores, the smoothness, the luster and especially the handle of the material. Since, under the influence of heat both the drying process and the above improvements are substantially accelerated, it is well known to heat the rollers or godets. To this end the godets are provided with double jackets and the heat carrier, e.g., water, thermal oil, steam or superheated steam is conveyed through the annular clearance between the two jackets.

In order to obtain optimum results it is very important to ensure the uniform temperature distribution across the whole width and circumference of the godet because, as has already been mentioned, the temperature exercises an influence upon the characteristics of the fibers and with endless fibers, any temperature differences on the width or circumference of the godets produces different characteristics over the fiber length. The obtainment of an even temperature distribution is especially important in those cases where the rollers or godets are to be heated up to high temperatures. However, high temperatures are necessary to meet the industry's demand for an ever-increasing production speed. The production speed in turn depends on the effectiveness of the treatment of a certain duration, i.e., on the temperature.

According to the Parent Application, this problem is solved by providing for the forced flow of the heat carrier through the annular clearance between the two jackets of the rollers or godets. This forced flow can be obtained by subdividing the annular clearance into several compartments with connecting channels for supplying and returning the heat carrier.

The higher the production speed, requiring the higher running speed of the godets, the higher must be the temperature on the jackets of the godets. Since the heat carrier flowing through the bearing shaft of the godet to heat the godet surface comes into contact with several pipes and other machine parts which cause a temperature loss, and since, because of the costs arising when heating the heat carrier up to a certain temperature, the latter should not be heated too much above the temperature which is to prevail on the jacket of the godet, attempts have been made to reduce heat losses to a minimum.

Heat losses are especially high at the points of contact between the godet and the bearing shaft, i.e., over the entire width of the godet, because here the heat is transferred to the oil used for lubricating the bearings of the shaft.

SUMMARY OF THE INVENTION

Taking the above described godet as a basis, substantially in accordance with the Parent Application, an object of the present invention is to provide a means for reducing the heat transfer from the godet onto the bearing shaft at the fitting areas necessary for the exact support of the godet.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

According to the present invention this is achieved by designing the metal fitting surfaces between the bearing shaft and godet to be intermittent or discontinuous. This is done to interrupt the axial even fitting surface and/or the radial circular fitting surface between the bearing shaft and the godet and to produce certain areas between the bearing shaft and godet which do not have direct contact with each other. The section of heat transfer at the fitting areas is thus reduced while the fit which is a pre-condition for the exact support of the godet is still maintained. The clearances are preferably filled with a heat insulating material and if necessary, the metal points of contact can also be separated from each other by a layer of heat insulating material.

DESCRIPTION OF THE DRAWINGS

The attached drawings show a godet according to the present invention with the bearing shaft.

FIG. 1 is a longitudinal section through a godet and its bearing shaft;

FIG. 2 is a cross section along the line II--II of FIG. 1; and

FIG. 3 is another embodiment of a longitudinal section through a godet and its bearing shaft.

The godet 2 which is connected to the bearing shaft 1, comprises an outer jacket 3 and a front wall 4 which is fastened to the outer jacket 3. An inner jacket 5 is fastened to the front wall 4, and extends a small distance from the outer jacket 3. Between the outer jacket and the inner jacket an annular channel 6 is provided which is subdivided into several compartments. A heating medium which is supplied through a centric pipe 7 in the bearing shaft 1 flows through the annular channel. At the front wall which faces the godet 2, the bearing shaft 1 containing the shrunk-on bearings 9 and 10 is provided with a mounting flange 11 which is fastened to the godet 2 by means of screws 12, from the direction of the front wall.

This mounting flange is provided with axial and radial fitting areas 13 and 14 respectively. From FIG. II it can be seen that both the axial and radial fitting areas 13 and 14 do not have any smooth surface but are provided with interstices 15 and 16 which are filled with a heat insulating material 17 and 18 respectively. The metal surfaces of contact between the bearing shaft 1 and the front wall 4 of the godet 2, which permit an undesired heat transfer, are thus reduced while the existing axial and radial fitting areas still ensure the true rotation of the godet.

It is also feasible to provide the rest of the fitting areas 13 and 14 also with a thin coating of heat insulating material in order to eliminate any contact of metal surfaces between the bearing shaft and the godet which can be heated up to 200.degree.C or more by means of the heating medium. The heat loss due to the heat transfer between the bearing shaft and the godet is therefore negligible and the outer jacket 3 of the godet 2 can be heated to a very high temperature. There is the further advantage that the bearing 9 and 10 of the bearing shaft 1 are not affected by the high temperature of the godet. As a consequence, the undesired heating of the lubrication oil necessary for the bearings 9 and 10 is eliminated.

In the embodiment of FIG. 3, a ring of heat-insulating material, 19 and 20, is disposed between the respective bearing surfaces 13 and 14 of the bearing shaft 1 and the godet 2. FIG. 3 also shows concentrically disposed, spaced-apart, inner and outer conduit means 7 and 21 axially disposed in the bearing shaft. The conduit means define an axial zone and an annular zone therebetween for the introduction and discharge of the heat transfer medium. The axial and annular zones in the bearing shaft communicate with the channel defined by the outer and inner cylindrical jacket. Advantageously, the outer conduit means 21 is spaced apart from the inner wall of the bearing shaft and can be supported on said inner wall of the bearing shaft by a sleeve means disposed in the spaced-apart area. The sleeve means can be made of a ceramic material.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be apparent to one skilled in the art are intended to be included.

Claims

What is claimed is:

1. A godet for installation in drawing units and roller dryers used for treating natural and synthetic fibers, which comprises an outer cylindrical jacket provided with a front end wall, an inner cylindrical jacket spaced from said outer cylindrical jacket to define a channel therebetween, means for introducing a forced flow of a heat transfer medium to the channel for heating said godet, and a bearing shaft means attached to the front end wall of said outer jacket by radial and axial fittings, said bearing shaft means being rotatably mounted in bearing means associated therewith, said radial and axial fittings having discontinuous metal contact surfaces and interstices provided between the bearing shaft and the front end wall of the outer jacket and said interstices being filled with a heat insulating material whereby heat losses by heat transfer from the outer jacket to the shaft means are reduced.

2. The godet as claimed in claim 1, wherein the axial fittings have a plurality of said metal contact surfaces each spaced from the other by one of said interstices.

3. The godet of claim 1, wherein the radial fittings have a plurality of said metal contact surfaces, each of said metal surfaces being curved and each being spaced from the other by one of said interstices.

4. The godet of claim 1, wherein the metal contact surfaces are each provided with a thin coating of heat insulating material.

5. A godet for installation in drawing units and roller dryers for treating natural and synthetic fibers, which comprises an outer cylindrical jacket provided with a front end wall, an inner cylindrical jacket spaced from said outer jacket to define a channel therebetween, means for introducing a forced flow of a heat transfer medium to the channel for heating said godet, a bearing shaft means attached to the front end wall by radial and axial fittings, said bearing shaft means being mounted rotatably in bearing means associated therewith and said radial and axial fittings having discontinuous metal contact surfaces between the bearing shaft and the front end wall, means being located adjacent to said metal contact surfaces for preventing heat losses by heat transfer from said front end wall to said bearing shaft means, said bearing shaft means including an inner conduit means and an outer conduit means spaced from each other, and said conduit means defining an axial zone and an annular zone therebetween for the introduction and discharge of the heat transfer medium to said channel defined between the outer and inner cylindrical jackets.

6. The godet of claim 5, wherein the bearing shaft means is provided with a cylindrical inner wall and said outer conduit means is spaced from and supported by sleeve means in contact with the inner wall.

7. The godet of claim 6, wherein the sleeve means is made of a ceramic material.