Abstract:
A method and arrangement is disclosed for removing oil from a roll, in which, inside a rotatable shell, there is a fixed axle beam, which supports loading shoes directed against the inner surface of the shell. An oil guide attached to the loading shoes creates an inwardly-directed jet of oil, next to and at a short distance from which a collector trough is located. The oil guide and an auxiliary guide attached to the collector trough guide and channel the oil jet against the collector trough. The oil is removed to an outlet pipe through a low gap in the bottom of the collector trough.

Description:
FIELD OF THE INVENTION 
     This invention relates to a method and arrangement for removing oil from a roll, in which, inside a rotatable shell, there is a fixed axle-beam, supporting loading shoes acting on the inner surface of the shell, and in which roll there are devices for removing oil from the roll, comprising an oil guide attached to the loading shoes, a collector trough, and oil-removal piping, of which the oil guide is arranged to form an oil jet directed into the roll, the removal of the oil from the roll being arranged to take place with the aid of the pressure difference. 
     BACKGROUND OF THE INVENTION 
     Problems with deflection-compensated rolls include oil frothing and poor oil removal from inside the roll. In addition to oil leaking from the loading shoes, oil may be sprayed against the inside of the roll shell to cool or heat it. It is important that the oil is collected as soon as possible from inside the roll, so that frothing of the oil, and thus the air mixed with it, remains as little as possible. When the roll rotates, a film of oil travels around its inner surface, colliding with the stationary loading shoes. In the solution according to U.S. Pat. No. 5,853,359, the lubricating oil colliding with the loading shoes is allowed to flow by gravity to a lower trough, from which it is sucked out of the roll. If the loading shoes are low down, a special scraper is used, from which the oil flows into the trough in a corresponding manner. Such a construction demands a considerable amount of space, which is not available in most rolls. A somewhat similar construction is disclosed in Finnish patent application 982045, in which the gravity-induced flow is directed to a special collection space, which may be located as a low construction on the outer surface of the cylindrical axle. WO publication 98/38381 discloses a special guide, to be attached to the loading shoes, by means of which a jet, directed towards a trough beneath, is formed from the film of oil traveling along the inner surface of the roll. In this case, the oil-removal guide must be set at a higher level, because removal takes place, at least partially, by gravity into the lower trough. A corresponding solution cannot be used in connection with a loading shoe set at a lower level. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method and an arrangement embodying it, which will permit the removal of oil in any position at all. 
     The method for removing oil from a roll, in which, inside a rotatable shell, there is a fixed axle beam, which supports loading shoes directed against the inner surface of the shell, and in which roll there are devices for removing the oil from the roll, comprising an oil guide attached to the loading shoes, a collector trough and oil-removal piping, of which the oil guide is arranged to create a jet of oil directed inside the roll and the transfer of the oil out of the roll is arranged to take place with the aid of a pressure difference, is characterized in that the collector trough is located a short distance from the oil jet and the related auxiliary guide, which, together with the oil guide is arranged to guide and channel the oil jet against the trough, and that the oil is removed to the outlet pipe through a low gap in the bottom of the collector trough. 
     The arrangement in a roll equipped with loading shoes, in which, inside a rotatable shell, there is a fixed axle beam, supporting the loading shoes directed against the inner surface of the shell, and in which shell there are devices for removing oil from the roll, comprising an oil guide attached to the loading shoes, a collector trough, and oil-removal piping, of which the oil guide is arranged to form an oil jet directed inside the roll and the transfer of the oil out of the roll is arranged to take place with the aid of a pressure difference, is characterized in that the collector trough includes an auxiliary guide and that it is located at a short distance from the oil guide of the loading shoe, in such a way that it turns the oil jet to the bottom of the collector trough, and that there is a gap in the bottom of the collector trough leading to the outlet pipe. 
     Utilizing the method according to the invention, oil is removed rapidly and with a good degree of control, in a small space. According to one preferred embodiment, each loading shoe incorporates a guide of the same width as the shoe, for creating an oil jet, whereas the collector trough receiving the oil and its auxiliary guide and removal pipe are essentially the same width as the roll shell. 
     These and other features and advantages of the invention will be more fully understood from the following detailed description of the invention taken together with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 shows a cross-section of a roll, in which an oil-removal arrangement according to the invention is attached to the loading shoes; 
     FIG. 2 shows a partly enlarged cross-section at the loading shoe, more precisely of the oil-removal arrangement located at its side; 
     FIG. 2 b  shows the operation of the oil-removal arrangement; 
     FIG. 3 shows another oil-removal arrangement according to the invention; 
     FIG. 4 shows an oil-removal arrangement according to the invention, located in an upper position; 
     FIG. 5 shows a variation of the oil guide, attached to one type of loading shoe; 
     FIG. 6 a  shows a variation of the oil-removal arrangement of FIG. 2 a;  and 
     FIG. 6 b  shows an oil-removal arrangement according to the invention, located in the upper position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the deflection-compensated roll  10  according to FIG. 1, there is a stationary axle  12 , on which the loading shoes  20  are installed. Here, reference number  20  is used to mark the moving part of the loading shoes, which, in this case, is a cylindrical component. The roll shell  11  is arranged to rotate in a known manner, with the aid of bearing devices ( 14 ). Loading shoes  20  press on roll shell  11 , in a manner that is, as such, known, while the related oil-feed system can be used to load the roll shell from inside, according to the desired profile. 
     With reference to FIG. 1, loading shoes  20  and the related oil guide  13  extend to the inner surface of roll shell  11 . According to FIG. 1, oil guides  13  are essentially the same width as loading shoes  20  and, at the shoes, guide the oil traveling along the inner surface of roll shell  11 , as an oil jet essentially in a radial direction to collector trough  19 . 
     The construction of the oil-removal devices is shown in detail in FIG. 2 a,  in which there is a partly enlarged cross-section at the loading shoe. Loading shoe  20  or more precisely its cylindrical part, move in a radial direction, according to the load of the loading shoe. Oil guide  13 , which throws the oil to collector trough  19 , which is formed by outlet pipe  15  and in this case sheet-metal casing  14 , is attached to this cylindrical part by means of bolts  18 . The end part  14 . 1  of the casing forms an auxiliary guide, which turns the oil jet, in the manner described later, to the bottom of the collector trough, in which there is a gap  16  connecting to outlet pipe  15 . This gap  16  is slightly narrower than the plate-like oil guide  13  and loading shoe  20 . Outlet pipe  15  and collector trough  19  extend continuously over the entire width of the row of loading shoes (see FIG.  1 ). Oil is led with the aid of connector pipe  17  from outlet pipe  15  to an external outlet channel. The removal of the oil can, as such, take place either by means of excess pressure or a vacuum. Excess pressure is created by feeding compressed air into the roll, whereas a vacuum is created with the aid of a vacuum pump connected to the outlet pipe. 
     Oil collection can be further improved by widening the oil guides and correspondingly the gaps of the outlet pipe. 
     Most of the collector trough can be formed by machining it into the axle, as shown in FIG. 6 a.  The same reference numbers as previously are used for functionally similar components. In this case, a small part of the collector trough is formed by sheet-metal strip  14 . 4 , which carries outlet pipe  15  and which is secured to axle  12  by means of bolts  14 . 3 . 
     According to FIG. 2 b,  the roll shell, which rotates rapidly in the direction S 1 , brings a flow of oil against loading shoe  20  and oil guide  13 , the kinetic-energy of the oil creating a damming pressure at the intersection of oil guide  13  and roll shell  11 . This creates an oil jet J 1 , which discharges along oil guide  13 , which is aimed in the direction of auxiliary guide  14 . 1  of collector trough  19 , which further leads it to the bottom of the collector trough, the other side of which is formed by outlet pipe  15 . A layer of oil, which prevents air from entering outlet pipe  15 , forms on top of gap  16  in the lower part of outlet pipe  15 . At the same time, this oil layer cancels the remaining kinetic-energy in the jet, calming the flow at this stage at the latest. The depth of the oil layer forming on top of gap  16  is adjusted by controlling the vacuum or excess pressure in outlet pipe  15 . The final cancellation of the jet in the trough can take place in some other way, as long as a layer of oil collects on top of the gap. 
     FIG. 3 shows a variation of the oil guide. This oil guide  13  is formed most simply by a flow surface shaped in the loading shoe, which is vertical in FIG. 3, but which continues as a hole, to which auxiliary guide  14 . 1  of collector trough  19  extends. In this case, oil guide  13  forms an oil jet in the same way, which can be easily directed to auxiliary guide  14 . 1  and from it onwards to the bottom of collector trough  19 . It is always essential for there to be a gap between oil guide  13  and auxiliary guide  14 . 1 , which permits the loading shoe to move radially. Except for the guide surfaces, the oil jet follows this narrow gap, so that its movement is very well controlled. 
     The oil-removal arrangement according to FIG. 4 according to the invention can be located in any position at all. In this case, oil guide  13  attached to loading shoe  20  forms the oil jet and turns it nearly as much as required, with auxiliary guide  14 . 1  forming part of the actual oil-removal arrangement only guiding it in a straight form to the bottom of the collector trough. The trough has a spiral shape, with outlet pipe  15  forming its inner part. The opening in its lower part is blocked at regular intervals, thus forming gaps  16  for transferring the oil to the operational outlet pipe. The suction opening  17 ′ in the end of the outlet pipe is shown in the figure by broken lines. 
     The oil-removal arrangement according to the invention can also be applied in connection with a shoe press roller, according to FIG. 6 b.  In this case, the embodiment corresponds to the oil-removal arrangement shown in FIG.  4 . In the shoe press roller embodiment, the shell  11  is the belt casing, which is usually about 3-5 mm thick. Despite the thinness of the belt casing, the oil-removal arrangement works well, as the belt casing is sufficiently stable immediately before loading shoe  20 . 
     In the case according to FIG. 2 b,  the flow energy of the oil is to a great extent cancelled already against the loading shoe and the guide in it. If a relatively more powerful jet, for example at a lower circumferential velocity, is desired, an oil guide  13  according to FIG. 5, for example, is used in which a curved oil-guide piece is attached to loading shoe  20 , which piece turns the oil layer on the inner surface of the roll shell  11 , with small losses, into an inwardly-directed jet, at which point an oil collector trough with an auxiliary guide is placed in the manner disclosed previously. 
     Although the invention has been described by reference to specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims.