KR100457171B1 - A method for regulation of the temperature in the end areas of the roll mantle of a variable-crown roll provided with glide and for compensating for an error in the diameter of the roll arising from thermal expansion in a roll - Google Patents

Abstract

The present invention relates to a method of adjusting the temperature of the roll mantle end zones of a variable crown equipped with a glide bearing and / or compensating for the error in the diameter of the roll resulting from thermal expansion. The roll mantle 12 of the roll 10 is loaded on the roll shaft 11 by hydraulic loading elements 17 and 17a which are loaded by the pressure medium and act on at least the inner surface of the roll mantle 12 in the 닢 plane direction. Is supported to be adjusted. Moreover, the roller mantle 12 is supported on the roller shaft 11 by hydraulic glide bearing elements 14, 14 a, 15, 16, which are loaded by pressure fluid and assembled in the end zones of the roller mantle. In this way a pressure medium is supplied to the end zones of the roll 10, the temperature and / or flow thereof being at a predetermined level, substantially at the same level as the middle zone temperature of the roll 10. Adjusted to maintain the temperature of the zones.

Description

How to adjust the temperature of the roll mantle end area of a variable crown roll with glide bearings, and how to compensate for the error in the diameter of the roll due to thermal expansion in the roll. A VARIABLE-CROWN ROLL PROVIDED WITH GLIDE AND FOR COMPENSATING FOR AN ERROR IN THE DIAMETER OF THE ROLL ARISING FROM THERMAL EXPANSION IN A ROLL}

The present invention relates to a method of adjusting the temperature of the roll mantle end zones of a variable crown equipped with a glide bearing and / or compensating for the error in the diameter of the roll due to thermal expansion in the roll. Pressure fluids) and are adjustablely supported on the roller shaft by hydraulic loading elements acting on the inner surface of the roller mantle in at least the 닢 planar direction, the roller mantle being scholarly in the end section and It is supported on the roller shaft by a load-bearing hydraulic glide bearing element.

Variable crowns are required and used in paper machines such as presses and calendars, and moreover such rolls are used in paper finishing devices such as supercalenders. Therefore, it is an important feature of the variable crown roll that the roll forms the back-up roll and the shroud, and the paper web passes through the shroud. The roll is provided with the necessary crown changing means, whereby the roll mantle is loaded in the 닢 plane direction, whereby the chop profile is controlled.

Initially, the tubular roll mantle of the roll was mounted by the roller bearing from the end on the roll axis, which was the most common solution for variable crown rolls. Such conventional journaling modes also have advantages, for example journaling can be performed in a rather simple manner, and so far the cost of the solution has been considered relatively reasonable. However, such a conventional journaling mode in which the roll mantle is mounted from the end to be fixed to the shaft is not suitable for almost all applications of the papermaking machine. From variable crowns in close contact with the back-up roll, very often such properties require that the roll mantle be able to move in the radial direction with respect to the roll axis. Considering adjusting the profile of the linear load across the entire axial length of the roll, the roll ends should also be movable in the radial direction with respect to the axis. This is because such characteristics have been developed to achieve this, so that the end bearings of the roller mantles are mounted on separate annular parts, which can move radially in relation to the roller axis. One such roll is described, for example, in EP 0,332,594.

However, the mounting of the rollers by roller bearings has caused a number of drawbacks to the manufacture and operation of the rollers. These shortcomings include many machines requiring roller bearings, problems caused by wear of the bearings, restrictions imposed by roller bearings on the oil used in the rollers, running speed limitations with roller bearings, and bearings. It includes rotational accuracy of. This is because there is a desire to abandon roller bearings, and recently a variable crown roll has been developed in which the roller mantle's journaling is achieved by glide bearings. Such rolls with glide bearings are described, for example, in US Pat. Nos. 5,060,357 and 5,111,563 and in Finnish Patent Applications 941107, 941991, 944272 and 950814. It is a problem of rolls with glide bearings that the roll end zones may be overheated, which has a very fatal effect on shock profile. Of course, the heating of the end zones is also a problem in other types of variable crowns that form back-up rolls and fins. One factor that is more important than others in excessive heating of the end zones is the fact that heat can be transferred from the roll through the papermaking web in the middle zone of the roll, whereas the ends are heated, which makes the web substantially narrower than the roll mantle. Because. In a roll with a glide bearing, the heating risk of the end zones can be greater because the heat generation in the glide bearing is higher than the roller bearing. Heat generation at the ends of the rolls with glide bearings is also particularly problematic because multiple glide bearing elements are effective at the same location on the inner circumference of the roll mantle. Part of the heat generated is, of course, carried from the zone of the ends along the oil flowing through the glide bearings, but usually the amount of oil is not large enough to carry the heat.

1 is a complete schematic side cross-sectional view of a roll having a glide bearing to which the method of the present invention may be applied.

FIG. 2 is a schematic sectional view taken along line II-II of FIG. 1; FIG.

Figure 3 is a schematic longitudinal sectional view of one end zone of a roll with a glide bearing of the first embodiment implementing the method of the present invention.

4 is a longitudinal sectional view similar to FIG. 3 in a second embodiment of the method according to the invention;

Fig. 5 is a longitudinal sectional view similar to Figs. 3 and 4 in a third embodiment of the present invention.

6 is a cross-sectional view of a roll showing a fourth embodiment of the present invention.

It is an object of the present invention to provide a unique method, whereby the excessive generation of heat generated in the roll end zone in which the glide bearing is installed and the problems caused by the heat generation are avoided. To achieve these objects, the present invention provides a pressure medium into the end zone of the roll, the temperature and / or flow thereof being at a predetermined level, substantially at the same level as the middle zone temperature of the roll. Adjusting to maintain temperature is a key feature.

The advantages provided by the present invention over prior art solutions are based on the very fact that the heating of the end section of the roller mantle is carried out under control. As a result, the axial temperature profile of the roll does not distort the shock profile. Further advantages and features of the present invention will emerge from the following detailed description of the invention.

In the following, the invention will be described by way of example with reference to the accompanying drawings.

Thus, Figures 1 and 2 are full schematic cross-sectional views of a turbula roll equipped with a glide bearing, so that Figure 1 is a cross-sectional view of the roll taken in the axial vertical plane, and Figure 2 is the roll of Figure 1 taken along line II-II. It is a cross section. In Figures 1 and 2, the roll is indicated generally by the reference numeral 10. The roll 10 is a variable crown roll, which comprises a fixed roll shaft 11, on which the tubular roll mantle 12 is assembled to rotate, the roll mantle 12 being a hydraulic loading element 17. And by a second set of hydraulic loading elements 17a acting in opposite directions. In the embodiment shown in Fig. 1, the hydraulic loading elements 17, 17a act in the w-plane direction, thereby making it possible to adjust the shape of the roll mantle 12 and to control the axial wedge profile of the roll. Do.

As shown in Figs. 1 and 2, the roll 10 is a roll exclusively mounted by a glide bearing, so the roll 10 has no conventional roller bearings assembled at the roll ends. The journaling of the roll 10 was achieved by glide bearing elements, the glide bearing elements acting in the double loading direction, i.e. in the lateral plane in the case of the roll as shown in Figs. Was marked. The first glide bearing element 14 acts in the 닢 direction, ie opposite the load, and the second glide bearing element 14a acts in the opposite direction. In the embodiment shown in FIGS. 1 and 2, it is further shown that the roll 10 is equipped with glide bearing elements 15, 15a acting in opposite directions across the loading direction. As described above, the roll 10 is a roll entirely equipped with a glide bearing, so that the glide bearing elements 16 and 16a also acting in the axial direction in the opposite direction are also provided, and these elements 16 and 16a are provided. It is supported by the intermediate ends of the oil films at the roll ends 13 and 13a. As shown in Figs. 1 and 2, the glide bearing elements 14, 15, 14a, 15a are supported in a radial direction, leaning against the inner side of the roll mantle 12 by an oil film. In the solution shown in Fig. 1, the radially acting glide bearing elements 14, 14a, 15, 15a are arranged in pairs, so that each of the two glide bearing elements are arranged side by side in the axial direction. However, the operation of the roll 10 does not necessarily require such an arrangement, since the journaling can also be carried out with a single glide bearing element alone. Such a solution is further detailed with reference to FIGS.

Figure 2 relates to an embodiment in which the glide bearings 14, 14a, 15, 15a are arranged to operate in the direction of the main loading plane and in the direction transverse to the plane. However, the glide bearing elements can also be arranged in a radial position, unlike in Fig. 2, in which case their reference numbers can also be different from those shown in Fig. 2. With respect to the axially acting glide bearing elements 16 and 16a, unlike FIG. 1, the axial movement of the roller mantle 12 is only one set of glide bearing elements 16 and 16a acting in the same plane in the opposite direction. Can be controlled by Alternatively, it may be a number of these axial glide bearing elements 16, 16a, which can be assembled uniformly spaced from one another, for example to act on the inner surfaces of the roller ends 13, 13a. The description described above in connection with FIGS. 1 and 2 has been described in relation to the general structure of a roll with a glide bearing.

3 shows a first embodiment of the method according to the invention. For the general structure of the roll 10, reference is made to the description relating to Fig. 1, in which reference numerals corresponding to Fig. 1 are used. However, although FIG. 3 uses glide bearing elements arranged in pairs in the roll 10 of FIG. 1, in the embodiment shown in FIG. 3 the glide bearing elements 14, 14a are arranged in one row. (15) is different from the description of FIG. Of course the solution as shown in FIG. 3 can also be applied in connection with a roll as shown in FIG. 1. In FIG. 3, the temperature adjustment of the end zones of the roll mantle 12 has been adjusted, so that the roll 10 with the glide bearing elements 14, 14 a, 15, 16 acting radially and / or axially at the roll ends. The supply of pressure fluids 20 and 21 of its own, separated from the hydraulic elements 17 and 17a of the power supply, was provided, so that the supply pipe 20a was installed in the adjusting device 22 to regulate the supply of pressure fluid. The regulating device 22 may be a device for adjusting the temperature (a device connected to a heat exchanger or a heat exchanger), in which case the regulating device 22 is a pressure supplied to the glide bearing elements 14, 14a, 15, 16. The temperature of the fluid is adjusted to a predetermined level. Generally, this predetermined level means that the temperature of the pressure fluid supplied to the glide bearing elements 14, 14a, 15, 16 is lower than the temperature of the pressure fluid passed to the hydraulic loading elements 17, 17a. The temperature of the pressure fluid passed through the hydraulic glide bearing elements 14, 14a, 15, 16 is limited by the running speed of the paper web (roll) and the loading situation of the roll. Sufficient accuracy can be achieved when the temperature is limited to vary according to a certain stage of the running speed of the papermaking web (roll).

Alternatively, the device according to FIG. 3 can be arranged so that the adjusting device 22 is a flow regulator, whereby the volume flow of the pressure fluid supplied to the glide bearing elements 14, 14a, 15, 16 is adjusted. Actual volumetric flow means that higher levels are adjusted ("additional fluid" is supplied to the glide bearing elements 14, 14a, 15, 16), in which case this large flow equalizes the temperature of the roll. In such a case, the temperature of the pressure fluid supplied to the glide bearing element may be equal to the temperature of the pressure fluid passed to the hydraulic loading elements 17 and 17a. The supply of additional fluid may be regulated via a separate line shown in FIG. 3, or the supply of additional fluid may for example be of the type described in Finnish Patent Application No. 935165 as glide bearing elements 14, 14a, 15, 16. A shoe with a constant fluid flow can be adjusted to be used. With the shoe having such a constant fluid flow, the volume flow of the pressure fluid passing through the shoe can be adjusted to a predetermined color. In addition, in the case of Fig. 3, the temperature of the pressure fluid is adjusted by the adjusting device 22, and the volume flow of the pressure fluid is in the shoe having the constant fluid flow used as the glide bearing elements 14,14a, 15,16. It is possible to use in combination adjusted by.

4 shows an embodiment of the invention wherein additional fluid is supplied to the end zone of the roll through a separate tube into the space between the roll mantle 12 and the roll shaft 11. The supply pipe for additional fluid is connected to a regulator 23, which acts as a device for adjusting temperature or as a device for adjusting volume flow. When the regulating device 23 adjusts the temperature, the fluid supply devices 20 and 21 supply a fluid of constant flow. In contrast, when the adjusting device 23 adjusts the volume flow, the temperature of the additional fluid can be kept unchanged. Thus, in the embodiment of Figure 4, the temperature adjustment of the roll end zones is performed by adjusting the temperature or volume flow of the additional fluid by supplying additional fluid to the end zones.

The embodiment shown in FIG. 5 is similar in other respects to the solution in FIG. 4 except that the additional fluid supply duct is installed in the two regulators 24, 25. One of the regulators acts as a device for regulating the temperature, for example, while the volumetric flow of additional fluid is regulated by the other regulator 25. Thus, in the embodiment of FIG. 5, both the temperature of the additional fluid and the volume flow are adjusted when considering the end zone temperature adjustment of the roll 10. FIG.

Figure 6 shows another embodiment of the present invention. In the embodiment of Figure 6, in fact the temperature at the end of the roll mantle is not adjusted, but in this solution the error resulting from thermal expansion in the form of the roll mantle is adjusted, which in turn causes a defect in the shock profile. As described above, the ends of the roll 10 become much hotter than the rest of the roll, thereby making the diameter of the roll mantle 12 larger due to thermal expansion and causing defects in the fin profile. This defect resulting from thermal expansion in the embodiment shown in FIG. 6 is covered and compensated for by the glide bearing elements 15 and 15a in which the roller mantle 12 acts in a direction transverse to the wedge plane. This covering of the roll mantle is shown exaggerated schematically and in dashed lines in FIG. 6. As can be seen from Fig. 6, when the roll wool mantle 12 is covered in the transverse direction, of course, its diameter is reduced in the direction of the 닢 plane, in which case the lower mantle in the 닢 plane by means of suitable spreading force. The diameter of can be kept equal across the entire axial length of the roll mantle. In other words, errors resulting from thermal expansion can be compensated for.

It is possible to use various combinations of the embodiments described above as well as error compensation resulting from temperature regulation and thermal expansion of the end zones of the mantle 10. In a different embodiment of the invention, the volume flow and / or temperature of the fluid supplied to the volume ie the end zones of the roll 10 and / or the glide bearing elements 14, 14a, 15, 16 and the roll mantle 12 The force required to cover this can be calculated in advance on a case by case basis. By the embodiment described above or by a combination of these embodiments, problems arising at the temperature of the end zones of the roller mantle with glide bearings can be controlled, and these temperatures and the problems resulting therefrom can be controlled, These temperatures and problems resulting therefrom can usually be smoothly controlled at operating conditions.

In the above, the present invention has been described by way of example with reference to the embodiment of the invention described with reference to the accompanying drawings. However, the invention is not limited to the embodiment that is illustrated in the drawings, but different embodiments of the invention may show variations within the scope of the invention as defined in the appended claims.

Claims (9)

In the method of controlling the temperature of the end section of the roll mantle 12 of the variable crown roll with glide bearings and / or the method for compensating the error of the roll diameter due to thermal expansion in the roll 10, The roll mantle 12 is adjustablely supported on the roll shaft 11 by hydraulic loading elements 17, l7a loaded by pressure fluid and acting on the inner side of the roll mantle in at least the 닢 plane direction. Supported on the roller shaft 11 by hydraulic glide bearing elements 14, l4a, 15, l5a, 16, l6a, which are loaded by fluid and mounted in the end section of the roller mantle, The method involves supplying a pressure fluid to the end zone of the roll 10 so as to maintain the temperature in the end zone of the roll mantle 12 at a predetermined level that is equal to the temperature in the middle section of the roll 10. The temperature and / or flow of the maneuver, characterized in that the temperature adjusting method of the end of the mantle and the diameter of the error compensation method. A pressure fluid, in which the temperature and / or flow rate can be adjusted, is fed through the roll's glide bearing elements 14, 14a, 15, 15a, 16, 16a to the end zones of the rolls and thus the glide bearing element 14 And 14a, 15, 15a, 16, 16a, acting as a pressure fluid for generating a load, and adjusting the temperature of the roll mantle end zone and the method of compensating the error of the roll diameter. The pressure fluid of claim 1 or 2, characterized in that the pressure fluid is supplied to an end section of the roll (10) directly acting on the inner side of the roll mantle (12) to equalize the temperature of the roll mantle (12). , Method of temperature adjustment of the roller mantle end zone and compensation of the error of the roller diameter. 3. The method according to claim 1, wherein the temperature of the pressure fluid supplied to the end section of the roll 10 is determined according to the running speed of the roll and the loading situation. Method of compensating error of roll diameter. 5. The method according to claim 4, wherein the temperature of the pressure fluid supplied to the end zone is adjusted to be varied in stages based on the running speed of the roll. The method of adjusting the temperature of the lower mantle end zone and the error compensation method of the diameter of the roll according to claim 1 or 2, characterized in that the pressure fluid supplied to the end zone passes through the heat exchanger 22 or the temperature adjusting device. . The method of adjusting the temperature of the roll mantle end zone and the method of compensating the error of the roll diameter according to claim 1 or 2, characterized in that the flow of the pressure fluid supplied to the end zone is adjusted by a separate flow adjusting device. A hydraulic loading shoe is used as the glide bearing element (14, l4a, 15, l5a, 16), whereby the volume flow of the pressure fluid passing through the shoe is adjusted to a predetermined level. Adjustment and compensation method characterized in that. 3. The pressure fluid supplied to the end section of the roll 10 in order to adjust for errors arising from the temperature of the roll diameter, according to claim 1 or 2, wherein the glide bearing elements 14, l4a, 15, l5a, 16) so that the glide bearing elements 15, l5a cover the roll mantle 12 in the direction transverse to the cut plane and reduce the diameter size of the roll mantle 12 in the cut plane direction, Method of temperature control of the roller mantle end zone and compensation of the error of the roller diameter.

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