Arrangement for removing oil in a roll

[0002] This application is a continuation of PCT application No. PCT/FI99/00783, filed Sep. 23, 1999, and claims priority on Finnish Application No. 982045, Filed Sep. 23, 1998, the disclosures of both of which applications are hereby incorporated by reference herein.

[0003] Not applicable.

[0004] An arrangement for removing oil in accordance with the present invention can be employed in all rolls in which there is a stationary support construction around which the roll mantle revolves and in which it is desirable to drain the oil that is gathered in the roll. Such rolls are, for example, variable-crown rolls in paper or board machines, rolls whose mantle can be shifted in the nip plane in relation to the stationary support construction, and extended-nip rolls.

[0005] In such rolls, a problem is whipping of the oil and poor drainage of the oil out of the roll interior. Oil is passed into the space between the loading members and the inner face of the roll mantle for purposes of lubrication, and, also, oil may be sprayed onto the inner face of the roll mantle for purposes of cooling. When the roll mantle revolves, said lubrication oil and cooling oil is gathered on the inner face of the roll mantle by the effect of centrifugal force, being carried along with the inner face of the revolving roll mantle. Said lubrication oil and cooling oil ought to be drained away from the inner face of the mantle as soon as possible in order that the oil could not be whipped when it collides against the loading members and against other support members. Excessive oil gathered on the inner face of the roll mantle also increases the amount of energy needed in order to rotate the roll mantle.

[0006] In the applicant's FI Utility Model No. 2920, an arrangement of equipment is described in connection with a variable-crown roll provided with loading shoes in order to prevent foaming of oil. This arrangement of equipment comprises a separate guide that drags against the inner face of the roll mantle and on said guide a face that guides the oil and by whose means the oil present on the inner face of the roll mantle is doctored and guided as an open flow into a collecting trough attached to the stationary roll axle.

[0007] In the applicant's FI Laid-Open Publication No. 98,318, an arrangement is described for draining of oil out of a roll which comprises a non-revolving roll axle, on which the roll mantle has been fitted revolving. Between the roll mantle and the roll axle, hydraulic loading elements have been fitted, which act upon the inner face of the roll mantle in the nip plane, which are supported on the roll axle, and which are loaded with a pressure medium. Said loading elements comprise pistons fitted in cylinder bores that have been formed in the roll axle and glide shoes supported against the inner face of the roll mantle, which glide shoes are provided with pockets separated by lateral ridges and by intermediate ridges and operating as lubrication spaces. Into at least one of the glide shoes in the roll, an oil drain groove has been formed, which groove communicates through a pipe, hose or equivalent with an oil drain duct provided in the roll axle, the oil being arranged to be drained out of the roll through the glide shoe/shoes.

[0008] In the EP Patent No. 812,994, a second equipment is described for guiding of an oil flow in connection with a variable-crown roll. The variable-crown roll comprises a stationary central axle, which is connected with hydraulically loaded cylindrical loading members, and a roll mantle revolving on support of bearings around the central axle. On the outer face of each loading member of circular section, two radial oil guide members have been fitted symmetrically. Further, at the outer ends of the oil guide members, guide plates extending tangentially to the outer face of the loading shoe have been fitted. When the roll is in a lower position and when the roll mantle revolves clockwise, the oil present on the inner face of the roll mantle strikes against the loading member from the forward side and is guided along the face of the loading member into the oil guide member, from which the oil falls down onto the end face of the central axle and from it further into a first oil collecting trough placed in connection with the central axle. From the first oil collecting trough, the oil is passed along a first duct to the centre of the central axle, from where the oil is passed out of the roll. When the roll is in an upper position and when the roll mantle revolves counterclockwise, the oil strikes against the loading members from the rear side, in which case the oil is again guided between the loading members into the ducts formed by the tangential guide plates. From here the oil proceeds as stripes of a width equal to the width of said ducts on the inner face of the roll mantle and strikes against spring-loaded doctors placed at the side of the central axle opposite to the loading members. From the faces of the doctors, which are spring-loaded against the inner face of the roll mantle, the oil falls down onto the end face of the central axle and from there further into a second oil collecting trough placed in connection with the central axle. From the second oil collecting trough, the oil is passed along a second duct to the centre of the central axle, from where the oil is passed out of the roll. The faces of the doctors that are placed against the inner face of the roll mantle are inclined. When the roll is in a lower position, the oil strikes against the wedge face of the doctor and presses the doctor against the spring, in which connection the oil can pass along the inner face of the roll mantle under the doctor.

[0009] The object of the present invention is to provide an efficient oil removing arrangement in a roll.

[0010] By means of the oil collecting equipments connected with the oil removing arrangements in accordance with the present invention, the oil is not collected by doctoring from the inner face of the roll mantle. Thus, in the oil collecting equipments, the curved face which guides the oil and which is placed closest to the inner face of the roll mantle is placed at a distance from the inner face of the roll mantle. In removing of oil taking place by means of doctoring, the friction between the doctor and the inner face of the roll mantle increases the power required to rotate the roll mantle.

[0011] When a curved face is used for guiding the oil, a sufficiently long face that guides the oil can be formed between the outer face of the support construction and the inner face of the roll mantle. With a sufficiently long face that guides the oil, the oil flow can calm down, in which case oil cannot return, as a result of vortex formation, back into circulation onto the inner face of the roll mantle. With a curved face, it is also possible to make efficient use of centrifugal force. Centrifugal force presses the oil flow against the curved face, in which connection the oil flow calms down.

[0012] By means of the curved faces of the oil collecting equipments employed in the present invention, economies of space are also obtained, in which case the support construction does not have to be machined so extensively in order to provide space. By means of curved faces, the volumes of the oil collecting equipments can be maximized.

[0013] In the following, the invention will be described with reference to the figures in the accompanying drawings, the invention being, however, not supposed to be confined to the details of said illustrations alone.

[0014] Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0015] FIG. 1 is a schematic sectional view of an oil removing arrangement in accordance with a first embodiment of the present invention in a variable-crown roll.

[0016] FIG. 2 is a schematic sectional view of the oil removing arrangement in accordance with the invention shown in FIG. 1 when the variable-crown roll operates as the upper roll of a nip.

[0017] FIG. 3 is a schematic axonometric view of the oil removing equipment employed in FIGS. 1 and 2.

[0018] FIG. 4 is a schematic sectional view of an oil removing syphon.

[0019] FIG. 5 illustrates the power consumption of a variable-crown roll as a function of the speed of rotation of the roll mantle with a roll provided with oil removing syphons alone and with a roll provided both with oil removing syphons and with an oil removing arrangement as shown in FIG. 1.

[0020] FIG. 6 is a schematic sectional view of an oil removing arrangement in accordance with a second embodiment of the invention in a variable-crown roll.

[0021] FIG. 7 is a schematic sectional view of the oil removing arrangement in accordance with the invention shown in FIG. 6 when the variable-crown roll operates as the upper roll of a nip.

[0022] FIG. 8 is a schematic axonometric view of the oil removing equipment employed in FIGS. 6 and 7.

[0023] FIG. 9 is a schematic sectional view of an oil removing arrangement in accordance with a third embodiment of the invention in a variable-crown roll.

[0024] FIG. 10 is a schematic sectional view of an oil removing arrangement in accordance with a fourth embodiment of the invention in a variable-crown roll.

[0025] FIG. 11 is a schematic sectional view of a variation of the oil removing arrangement shown in FIG. 10 in a variable-crown roll.

[0026] FIG. 12 is a schematic axonometric view of the oil removing equipment employed in FIGS. 10 and 11.

[0027] FIG. 13 is a schematic sectional view of a first embodiment of the invention to which an oil guide has been added.

[0028] FIG. 14 is a schematic sectional view of an embodiment of an oil guide.

[0029] FIG. 15 is a schematic sectional view of a second embodiment of an oil guide.

[0030] FIG. 1 shows a first embodiment of the oil removing arrangement in accordance with the invention in a variable-crown roll 10. In the situation shown in FIG. 1, the variable-crown roll 10 is in a lower position, and the sense of rotation S of the roll mantle 12 is counterclockwise. In the situation shown in FIG. 2, the variable-crown roll 10 is in an upper position, and the sense of rotation S′ of the roll mantle 12 is clockwise. FIG. 3 is a schematic axonometric view of the oil collecting equipment 90 shown in FIGS. 1 and 2. FIG. 4 is a sectional view of the oil removing syphon employed in this embodiment, and FIG. 5 illustrates the power requirement of the roll as a function of the speed of rotation of the mantle 12 in a situation in which the oil collecting equipment 90 is employed and in a situation in which no oil collecting equipment 90 is employed.

[0031] The variable-crown roll 10 shown in FIG. 1 comprises a stationary support construction 11 of substantially circular section and a roll mantle 12 revolving counterclockwise S around said support construction, which roll mantle is supported from its inner face 12′ on the support construction 11 by means of at least one hydraulically loaded loading member 13, by means of which loading member the roll mantle 12 can be loaded against a backup roll 20 which forms a nip N with the variable-crown roll. In the support construction 11, at the loading member 13, there is a plane top face 11bdiverging from the circular form. Further, the mantle 12 is supported on the support construction 11 by means of hydraulically adjustable support members 14a, 14bplaced at the side of the support construction 11 opposite to the loading member 13 in view of regulation of the linear load. In these so-called counter-zones, the spacing of the support members 14a, 14bin the longitudinal direction of the roll is less dense than the spacing of the loading members 13 at the nip N. In FIG. 1, the axial nip plane Y—Y of the roll and the axial neutral plane X—X placed perpendicularly to the nip plane Y—Y on the central axis of the roll are also shown. In the variable-crown roll, lubrication oil is fed between the loading member 13 and the inner face of the roll mantle 12. In the variable-crown roll, it is further possible to spray oil onto the inner face 12′ of the roll mantle 12 for purposes of cooling. When the roll mantle 12 revolves, the lubricating oil and cooling oil is gathered on the inner face of the roll mantle, from which it ought to be passed out of the roll.

[0032] In a variable-crown roll, the roll mantle 12 is loaded by means of the loading members 13 exclusively in order to compensate for bending. In a roll with a mobile mantle, the mantle 12 is both shifted in relation to the support construction 11 and loaded against a backup roll.

[0033] The oil collecting equipment 90 shown in FIG. 3 comprises an oil guide plate 91, which extends across the axial direction of the roll mantle and which complies with the curve form of the inner face 12′ of the roll mantle 12. The oil guide plate 91 is provided with a straight forward edge 91a, with a curved rear edge 91b, and with straight lateral edges 91c, 91d. Each lateral edge 91c, 91dof the oil guide plate 91 is provided with a radial side wall 93, 94 directed towards the support construction 11. The curved rear edge 91bof the oil guide plate 91 is connected with a curved rear wall 92 directed towards the support construction 11. The distance of the middle part of the curved rear wall 92 from the forward edge 91aof the oil guide plate 91 is smaller than the distance of the lateral portions of the curved rear wall 92 from the forward edge 91aof the oil guide plate 91. The side walls 93, 94 extend from the forward edge 91aof the oil guide plate 91 up to a distance from the rear edge 91bof the oil guide plate 91, in which case oil removing openings 95, 96 remain at the rear corners of the oil guide plate. The sense of rotation S of the roll mantle is also indicated in the figure.

[0034] When the oil E gathered on the inner face 12′ of the roll mantle 12 collides against the loading shoes 13 in the sense of rotation S of the roll mantle 12, part of the oil flows along the side walls of the loading shoes 13 onto the plane top face 11bof the support construction 11 and from there further along the circumferentially inclined outer face 11″ of the support construction 11 in the direction opposite to the sense of rotation S of the roll mantle 12. On the other hand, part of the oil splashes back into the space between the oil guide plate 91 and the outer face 11″ of the support construction 11 in the way indicated by the arrows E₁and E₂. The oil that travels between the outer face 11″ of the support construction and the oil guide plate 91 in the direction opposite to the sense of rotation S of the roll mantle 12 collides against the curved rear wall 92 of the oil collecting equipment 90, in which connection the oil is guided through the openings 95, 96 provided at the rear corners of the oil collecting equipment 90 to the roll ends.

[0035] In the embodiment shown in FIGS. 1 and 2, two oil collecting equipments 90, 90aare employed. In the situation of FIG. 1, in which the roll is in a lower position and the sense of rotation S of the roll is counterclockwise, an oil collecting equipment 90 opening against the loading member 13 is employed for collecting of oil, and in the situation of FIG. 2, in which the roll is in an upper position and the sense of rotation S′ of the roll is clockwise, an oil collecting equipment 90 opening towards the support member 14bof the counter-zone is employed. The forward part of the oil collecting equipment 90 can be attached to the support construction 11, for example, by means of projections 97 attached to the oil collecting equipment 90, which projections are attached to the support construction 11 by means of bolts 98. The rear part of the oil collecting equipment 90 can be attached to the support construction 11 in a similar way by means of bolts. The first oil collecting equipment 90 is opened against the loading member 13, and the second oil collecting equipment 90ais opened against the loading member 14bof the counter-zone.

[0036] In FIGS. 1 and 2, in the roll, the oil collecting equipments 90, 90ahave been placed on the right half of the support construction 11 only, but the left half of the support construction 11 can also be provided with oil collecting equipments. In a situation in which the right half and the left half of the support construction 11 have been provided with oil collecting equipments as shown in FIGS. 1 and 2, removing of oil operates in all roll positions and with both senses of rotation. Such a roll can be placed as an upper roll or lower roll at a nip, and the sense of rotation of the roll can be clockwise or counterclockwise in both positions.

[0037] In FIGS. 1 and 2, the roll is provided with two oil collecting equipments 90,90a, but the roll can, of course, also be provided with one oil collecting equipment only. In such a case, in the situation of FIG. 1, the roll is provided with an oil collecting equipment 90, and in the situation of FIG. 2 the roll is provided with an oil collecting equipment 90a. If the sense of rotation of the roll is clockwise in FIG. 1, the oil collecting equipment 90 is placed on the left half of the support construction, and if the sense of rotation of the roll is counterclockwise in FIG. 2, the oil collecting equipment 90ais placed on the right half of the support construction.

[0038] In the oil collecting equipment 90 shown in FIG. 3, the first oil guide face consists of a curved oil guide plate 91, and the second oil guide face consists of the curved outer face 11″ of the support construction 11. In a situation in which the cross section of the support construction 11 is not substantially circular, as the second oil guide face it is possible to use a second oil guide plate, in which case the oil collecting equipment 90 is formed as a box.

[0039] FIG. 4 shows an oil removing syphon 100 placed at each end of the roll, by means of which syphon the oil E guided to said roll end by means of the oil removing equipment 90 shown in FIG. 3 is guided into a radial oil drain duct 101 of the oil removing syphon 100 and along said duct further into the central portion of the roll, from which the oil is passed along an axial oil drain duct 102 out of the roll.

[0040] In FIG. 5, the curve f₁illustrates a situation in which exclusively oil removing syphons 100 are employed at the ends of the roll, and curve f₂illustrates a situation in which both oil removing syphons 100 and an oil collecting equipment 90 in accordance with the first embodiment of the invention are employed. The curves shown in the figure have been measured in a situation in which oil is sprayed onto the inner face of the roll mantle for purposes of cooling as an invariable flow of 150 liters per minute. It is seen from the figure that the power required to rotate the roll mantle is, at all speeds of rotation, lower when an oil removing arrangement in accordance with the first embodiment of the invention is used f₂, compared with a situation in which exclusively oil removing syphons 100 are used at the roll ends f₁.

[0041] In FIG. 6, an oil removing arrangement related to a second embodiment of the invention has been applied to a variable-crown roll whose support construction is of substantially rectangular section. FIG. 7 illustrates a roll as shown in FIG. 6 while fitted as an upper roll at a nip. FIG. 8 illustrates the oil collecting equipment 60 employed in FIGS. 6 and 7.

[0042] The oil collecting equipment 60 shown in FIG. 8 comprises a bottom plate 61, to which ducts 62 extending through the bottom plate 61 have been fixed. To these ducts 62, the outer wall 63 of the oil collecting equipment has been attached, which outer wall is provided with openings passing into the interior of the ducts 62. The outer wall 63 consists of a portion 63aparallel to the bottom plate 61, of a subsequent U-section portion 63b, and of a subsequent curved portion 63c. The oil collecting equipment 60 further comprises a curved partition wall 64 attached to one edge of the bottom plate 61, which partition wall runs at a distance from the curved portion 63cof the outer wall 63 and extends to the area of the U-section portion 63bof the outer wall. The oil collecting equipment 60 may consist of a number of modules, which are installed one after the other in the axial direction of the roll, or the oil collecting equipment 60 may consist of one module extending across the entire axial direction of the roll.

[0043] In the situation shown in FIG. 6, the bottom plate 61 of the oil collecting equipment 60 has been mounted against the side face 11aof the support construction 11, in which case the ducts 62 extending through the bottom plate 61 are positioned in the radial oil drain ducts 50 passing into the central portion of the support construction 11. The oil E gathered on the inner face 12′ of the roll mantle 12 collides against the loading shoe 13 in the counterclockwise sense of rotation S of the roll mantle, in which connection the oil is disrupted and flows along the side edge of the loading shoe 13 down onto the top face 11bof the support construction 11. This oil is guided in the space between the curved portion 63cof the outer wall 63 of the oil collecting equipment 60 and the curved partition wall 64 into a pocket formed by the outer wall 63, in which pocket the level of oil starts rising. After the oil level has risen sufficiently, the oil flows through the ducts 62 attached to the outer wall 63 into the radial oil drain ducts 50 and further along the axial oil drain duct 51 in the central portion of the support construction 11 out of the roll.

[0044] In the situation shown in FIG. 7, the oil E gathered on the inner face 12′ of the roll mantle 12 collides against the support members 14bof the counter-zone in the clockwise sense of rotation S′ of the roll mantle, in which connection the oil is disrupted and flows along the side face of the support member 14bof the counter-zone and along the side face 11aof the support construction 11 through the space between the bottom plate 61 of the oil collecting equipment 60 and the straight portion 63aof the outer wall 63 into a pocket formed by the bottom plate 61 and by the partition wall 64, in which pocket the oil level starts rising. After the oil level has risen sufficiently, the oil flows through the ducts 62 attached to the outer wall 64 into the radial oil drain ducts 50 and further along the axial oil drain duct 51 in the central portion of the support construction 11 out of the roll.

[0045] The use of the oil collecting equipment 60 shown in FIG. 8 does, of course, not require that the roll is provided with a support construction 11 of substantially rectangular section as shown in FIGS. 6 and 7. The side face of the support construction 1 can also be, for example, arc-shaped, in which case the bottom plate 61 of the oil collecting equipment 60 is similarly arc-shaped.

[0046] In the embodiments shown in FIGS. 6 and 7, just one oil collecting equipment 60 is employed, which rests against one side face 11aof the support construction 11. In the roll, it is, of course, also possible to employ two oil collecting equipments, in which case the other oil collecting equipment is placed at the opposite side of the support construction. When the roll is provided with two oil collecting equipments placed at opposite sides of the support construction, the removal of oil can be made to operate in all roll positions and with all senses of rotation.

[0047] FIG. 9 illustrates a third embodiment of the oil removing arrangement in accordance with the invention in a variable-crown roll. In this embodiment, the principal nip plane Y′—Y′ forms an angle α with the vertical plane T. The angle α can be, for example, in a range of about 0-45°. Besides the principal nip plane Y′—Y′, the roll also forms a secondary nip plane Y₁with a second backup roll 21 at the secondary loading shoe 15. The figure also shows an auxiliary plane X′—X′, which passes through the centre point O of the circle that follows the outer face of the roll mantle and which intersects the principal nip plane Y′—Y′ at an angle of 90°. The sectional form of the support construction 11 of the variable-crown roll is I-shaped, and the sense of rotation S of the roll mantle 12 is counterclockwise.

[0048] The oil collecting equipment 70 shown in FIG. 9 comprises an oil guide plate 71 extending across the axial length of the roll mantle 12, which oil guide plate consists of a curved upper portion 71a, of a first straight portion 71bfollowing said curved portion after a bend, and of a second straight portion 71cfollowing said first straight portion after a bend. The oil guide plate 71 has been attached to the inclined portion of the top face of the support construction 11 from its curved upper portion 71aby means of fastening means, for example bolts 72. Further, if necessary, the second straight portion 71cof the oil guide plate 71 can be attached to the middle portion of the support construction 11. The oil guide plate 71 extends across the axial direction of the roll, and the edges of the oil guide plate 71 can be provided with side walls directed towards the support construction 11 (not shown in the figure).

[0049] The oil removing arrangement further comprises an oil collecting trough 80 fitted in the lower portion of the support construction 11 and an axial oil drain duct 82 fitted in the middle portion of the support construction 11 on the auxiliary plane X′—X′, which oil drain duct communicates with the oil collecting trough 80 through an oil drain pipe 81. Above the bottom face of the oil collecting trough 80, in the middle portion of the support construction 11, an oil drain hole 84 has been formed, which extends through the middle portion of the support construction 11.

[0050] When the oil E gathered on the inner face of the roll mantle 12 collides against the loading members 13 in the sense of rotation S of the roll mantle 12, part of the oil flows along the side face of the loading members 13 onto the top face 11bof the support construction 11. After this the oil flows along the inclined top face 11bof the support construction 11 between the loading members 13 into the space B1 between the oil guide plate 71 and the top face 11aof the support construction 11, out of which space the oil flows further, through the duct between the curved top portion 71aof the oil guide plate 71 and the inclined portion of the top face of the support construction 11, onto the first straight portion 71bof the oil guide plate 71 and along the inclined face of said plate portion onto the second straight portion 71cof the oil guide plate 71 and along its inclined face to the vicinity of the side wall of the middle portion of the support construction 11, from where the oil falls down into the oil collecting trough 80 placed in the lower portion of the support construction 11.

[0051] When the oil E gathered in the inner face of the roll mantle 12 collides against the loading members 13 in the sense of rotation S of the roll mantle, part of the oil splashes back against the sense of rotation S of the roll mantle so that it falls from the right side of the support construction 11 into the oil collecting space B2 formed by the bottom portion of the support construction 11, out of which space the oil flows further through the oil drain hole 84 provided in the support construction 11 into the oil collecting trough 80.

[0052] From the oil collecting trough 80, the oil is removed, by the effect of the pressure present inside the roll mantle 12, along the oil drain pipe 81 into the axial oil drain duct 82 and along said duct out of the roll. In the oil drain pipe 81, there are air holes 83, which permit the oil level to rise in the oil collecting trough 80 up to the air holes 83. When the oil level is lower than the level of the air holes 83, air flows out of the interior of the roll mantle 12 through the holes 83. When the oil level in the oil removing trough 80 rises, the air holes 83 remains below the oil level, in which case oil starts being discharged properly out of the oil removing trough 80.

[0053] In FIG. 10, an oil removing arrangement related to a fourth embodiment of the invention is applied in a variable-crown roll, whose support construction 11 is of substantially circular section. In FIG. 11, an oil removing arrangement related to the fourth embodiment of the invention is applied in a variable-crown roll whose support construction 11 is of substantially I-section. FIG. 12 shows an oil collecting trough 30 employed in FIGS. 10 and 11.

[0054] FIG. 12 shows an oil collecting equipment 30 connected with the oil removing arrangement illustrated in FIGS. 10 and 11. The oil collecting equipment 30 comprises a rectangular outer wall 31 and a rectangular inner wall 32 placed at a distance from said outer wall. The outer wall 31 and the inner wall 32 have been bent into a curve form in the direction of the circumference, and they extend across the axial length of the roll mantle 12. The forward edge of the inner wall 32 of the oil collecting equipment 30 extends, in the direction of the circumference, further than the forward edge of the outer wall 31 of the oil collecting equipment 30. The edges of the outer wall 31 and of the inner wall 32 of the oil collecting equipment 30 have been interconnected by means of radial side walls 33, 34. The rear edges of the outer wall 31 and of the inner wall 32 of the oil collecting equipment 30 have been fixed to an axial oil guide duct 35. On the outer face of the forward edge of the outer wall 31 of the oil collecting equipment 30, there is a row of pins 36, by whose means the outer wall 31 is kept at a distance from the inner face 12′ of the roll mantle 12. The radial distance between the outer wall 31 and the inner wall 32 of the oil collecting equipment 30 is larger at the forward edge of the outer wall 31 than at the rear edges of the outer wall 31 and the inner wall 32, in which case they form a gap between them, which gap collects oil.

[0055] The interior space in the oil collecting equipment 30 shown in FIG. 12 has been divided into two parts by means of two oil guide plates 37a, 37b. The oil guide plates 37a, 37bhave a common starting point A1 in the middle portion of the forward edge of the oil collecting equipment 30. The first oil guide plate 37ais directed from this common starting point A1 in curve form towards the first rear corner of the oil collecting equipment 30, and the second oil guide plate 37 is directed from this common starting point in curve form towards the second rear corner of the oil collecting equipment 30. In the oil guide duct 35, at said rear corners, there are openings 38, 39 opening into the interior of the oil collecting equipment 30, through which openings the oil guided by the oil guide plates 37a, 37bis carried into said oil guide duct 35.

[0056] In the oil collecting equipment 30 shown in FIG. 12, the oil gathered on the inner face 12″ of the roll mantle 12 is passed through the openings at the forward edge of the oil collecting equipment 30 in the direction of the arrows Ea, Eb into either part of the oil collecting equipment 30. In each part, the oil is guided by means of the oil guide plate 37a, 37b, the outer wall 31, the inner wall 32, and by means of the side wall 33, 34 through said openings 38, 39 into the oil guide duct 35. The circumferential flow of the oil is turned by means of the curved oil guide plates 37a, 37btowards the axial direction in order that no abrupt change of 90° should occur in the flow direction of the oil as the oil passes into the oil guide duct 35.

[0057] In FIG. 10, the oil collecting equipment 30 has been attached to the outer face 11″ of the support construction 11 of substantially circular section by means of an actuator 40, e.g. a cylinder-piston construction, by whose means the oil collecting equipment 30 and the connected axial oil guide duct 35 can be pivoted around the central axis of the oil guide duct 35 between an outer and an inner position. In the outer position, the pins 36 provided on the outer face of the forward edge of the outer wall 31 of the oil collecting equipment 30 are in contact with the inner face 12′ of the roll mantle 12. In the inner position, the outer wall 31 of the oil collecting equipment 30 is at a distance from the inner face 12′ of the roll mantle 12. The oil guide duct 35 connected with the oil collecting equipment 30 is placed on the neutral plane X—X, and each end of the oil guide duct 35 communicates, through radial oil guide ducts 50, with an axial oil drain duct 51 placed in the central part of the support construction 11. When the oil collecting equipment 30 is in the outer position, the forward edge of the outer wall 31 of the oil collecting equipment 30 guides oil that has gathered on the inner face 12′ of the roll mantle 12 into the oil collecting equipment 30, from which it is passed into the axial oil guide duct 35 and, through the connected radial oil guide ducts 50 and through the axial oil drain duct 51 placed in the centre of the support construction 11, out of the roll.

[0058] In the embodiment shown in FIG. 10, on the neutral plane X—X, at both sides of the support construction, there are oil collecting equipments 30,30a. In the figure, the oil collecting equipment 30 placed at the left side is in the outer position, and the oil collecting equipment 30aplaced at the right side is in the inner position. When the roll mantle 12 revolves counterclockwise S, the oil collecting equipment 30 placed in the outer position at the left side forms a gap opening against the sense of rotation S of the roll mantle, by means of which gap the oil gathered on the inner face 12′ of the roll mantle can be collected into the oil collecting equipment 30. In such a case, the oil collecting equipment 30aplaced at the right side is in the inner position. As the roll mantle 12 revolves clockwise, i.e. opposite to the arrow S, the oil collecting equipment 30 placed at the left side is shifted to the inner position, and the oil collecting equipment 30aplaced at the right side is shifted similarly to the outer position. When the roll mantle 12 revolves clockwise, the oil collecting equipment 30aplaced at the right side in the outer position forms a gap opening against the sense of rotation of the mantle 12, by means of which gap oil gathered on the inner face 12′ of the mantle 12 can be collected into the oil collecting equipment 30a.

[0059] In the embodiment shown in FIG. 11, each end of the axial oil guide duct 33 connected with the oil collecting equipment 30 communicates with the radial oil guide ducts 50, by whose means the oil is guided into the axial oil drain ducts 52 fitted in the middle part of the roll at the side of the vertical part of the support construction 11. By means of these axial oil drain ducts 52 the oil is passed out of the roll. At each side of the support construction 11, there are oil collecting equipments 30, 30a, and they are controlled in a way similar to that shown in FIG. 1. Here the oil collecting equipments 30, 30ahave been interconnected by means of a rod 41 extending through the vertical part of the support construction 11. The oil collecting equipments 30, 30ahave been supported by means of articulation points on the ends of the rod 41, and the middle part of the rod 41 has been supported by means of an articulation point on a pivoting device 42, which is again supported by means of an articulation point on the vertical part of the support construction 11. When the pivoting device 42 is pivoted, the left oil collecting equipment 30 can be taken to use when the roll mantle revolve s counterclockwise S, and the right oil collecting equipment 30acan be taken to use when the roll mantle revolves clockwise.

[0060] As the axial oil guide duct 35 of the oil collecting equipment 30 shown in FIG. 12 is attached to the support construction 11 exclusively from its axial ends, bending of the middle part of the support construction 11. does not affect the oil collecting equipment 30, but the pins 36 on the outer wall 31 of the oil collecting equipment 30 remain in contact with the inner face 12′ of the roll mantle 12 over the entire axial length.

[0061] In FIGS. 10 and 11, the roll is provided with two oil collecting equipments 30, 30a, but, of course, the roll can also be provided with one oil collecting equipment only. In such a case, in the situation of FIG. 10, the roll is provided with the oil collecting equipment 30, and in the situation of FIG. 11 the roll is provided with the oil collecting equipment 30a. In such a case, it is not necessary to use the actuator 40, by whose means the oil collecting equipment 30, 30ais supported on the support construction 1, but the oil collecting equipment 30, 30acan be supported on the support construction 11 rigidly in the outer position.

[0062] FIG. 13 shows an oil guide 110, which has been added to the embodiment shown in FIG. 1. The oil guide 110 is placed before the loading member 13, as viewed in the sense of rotation S of the roll mantle 12, and the oil guide forms an inclined plane from the side face of the loading member 13 to the curved outer face 11″ of the support construction 11. When the oil E carried along with the roll mantle 12 collides against the loading members 13, part of the oil flows along the side face of the loading member 13 down onto the substantially horizontal top face 11bof the support construction, from which the oil E seeks its way, with the aid of gravity, into the oil collecting equipment 90. In particular the oil that flows slowly along the top face 11bof the support construction 11 tends to be subjected to vortex formation arising from air flows present in the roll, in which case part of this oil E has access back onto the inner face 12′ of the roll mantle 12. The situation can be improved by providing the top face 11bof the support construction 11 with an oil guide 110, along which the oil is guided more efficiently into the oil collecting equipment 90.

[0063] FIG. 14 is a schematic sectional view of an oil guide 110 which can be used. The sectional form of the oil guide 110 is substantially that of a right-angled triangle. The vertical wall 112 of the oil guide 110 is placed against the loading member 13, and the horizontal wall 113 of the oil guide 110 is placed against the top face 11bof the support construction 11. The wall 111 placed opposite to the right angle forms an inclined oil guide plane, along which the oil E that collides against the loading member 13 is guided into the oil collecting equipment 90. The vertical wall 112 that is placed against the loading member 13 remains at a distance from the top face of the loading member 13 and from the inner face 12′ of the roll mantle 12. Thus, the oil E is allowed to collide against the loading member 13, after which the oil that flows along the side face of the loading member 13 is guided along the inclined oil guide plane 111 into the oil collecting equipment 90.

[0064] FIG. 15 is a schematic sectional view of a second oil guide 110 which can be used. This embodiment differs from the embodiment shown in FIG. 14 in respect of the shape of the oil guide plane 111a. In stead of an inclined plane, herein a curved face 111ais used, along which the oil E colliding against the loading member 13 is guided into the oil collecting equipment 90.

[0065] In a roll, it is possible to use a number of oil guides 110 so that an oil guide 110 is fitted in front of each loading member 13, as viewed in the sense of rotation of the roll mantle. It is also possible to imagine that one oil guide 110 which extends across the entire axial length of the roll mantle 12 is fitted ahead of the loading members 13.

[0066] The use of such an oil guide 110 is, of course, not restricted to the situation illustrated in FIG. 1 alone, in which it is used in connection with a loading member 13. An oil guide 110 can be used, for example, in a situation as shown in FIG. 2 in connection with a support member 14bof a counter-zone, in a situation as shown in FIG. 6 in connection with a loading member, and in a situation as shown in FIG. 7 in connection with a support member 14bof a counter-zone.

[0067] In the embodiments shown in FIGS. 1 and 6, the forward edge of the outer wall 63, 91 of the oil collecting equipment 60, 90, which outer wall guides the oil, extends very close to the side walls of the loading members 13. The distance between the outer wall 63, 91 and the side walls of the loading members 13 is favourably in a range of about 10 to 20 mm. In the situation shown in FIG. 2, a corresponding distance is employed between the support member 14bof the backup zone and the forward edge of the outer wall 91aof the second oil collecting equipment 90a.

[0068] In the embodiments shown in FIGS. 1 and 6, in the oil collecting equipments 60, 90, a sufficiently long oil guide face 63, 91 is employed in order that the oil flow to be drained could be stilled. As the centrifugal force presses the oil flow against the oil guide face 63, 91, the oil flow cannot be disintegrated and atomized. As measured from the edge of the loading member 13 to the bottom of the oil removing equipment 63, 91, the circumferential length is larger than 20° but smaller than 180°. Said distance is preferably in a range of 90° to 120°.

[0069] By means of the oil removing arrangements described above, efficient removal of oil is achieved from the inner face of the roll mantle. By means of curved oil guide faces connected with the oil removing arrangements, oil is collected out of the space between the support construction 11 and the mantle 12 of the roll, after which the direction of flow of the oil is turned into an axial direction. After this, the oil can be passed to the ends of the roll, from which it is removed by means of oil removing syphons. A second possibility is to pass the oil into the central portion of the roll and from there further out of the roll. In both cases, attempts are made to take advantage of the kinetic energy of the oil as efficiently as possible when the oil is passed out of the roll.

[0070] In the following, the patent claims will be given, and the details of the invention can show variation within the scope of the inventive idea defined in said claims and differ from what has been stated above by way of example only.

[0071] It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.