Abstract:
Apparatus for aligning a refining disc is a refiner is disclosed, the apparatus including a first wedge slidable along a support for the axle package of the refining disc, a second wedge disposed between the first wedge and a bearing housing in which the rotatable axle of the axle package is journalled, the second wedge being slidable transversely to the slidable movement of the first wedge, a controller for controlling displacement of the first wedge, a support for a bearing housing, which includes a recess for the support and a complimentary recess, the support including a convex contact surface to engage the recess and being displaceable with respect to the complimentary recess.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a device for aligning the refining disc of a refining apparatus in which lignocellulose-containing material is disintegrated and refined, which device for aligning is intended to be arranged in a support for supporting the axle package of the refining apparatus, which axle package comprises the rotary refining disc of the refining apparatus, a rotary axle to which the rotary refining disc is attached, and a bearing housing in which the axle is journalled by means of bearings arranged in the bearing housing, where the support is intended to rest on a ground surface. The present invention also relates to such a device comprising a first wedge-shaped member, which is slidable in a direction along the ground surface, and a second wedge-shaped member provided between the first wedge-shaped member and the bearing housing of the axle package, which second wedge-shaped member is slidable in a direction transverse to the sliding direction of the first wedge-shaped member, and the first wedge-shaped member when displaced in its sliding direction, is arranged to displace the second wedge-shaped member in its sliding direction. The present invention also relates to a control device for displacing the first wedge-shaped member. The present invention further relates to a support for supporting the axle package of a refining apparatus comprising such a device, and to a refining apparatus comprising such a support. 
       BACKGROUND OF THE INVENTION 
       [0002]    For highly concentrated refining, CTMP, TMP, fluffing and highly concentrated grinding of sack paper and other lignocellulose-containing material, refining apparatus or disc refiners are used. Examples of refining apparatus are described in U.S. Pat. No. 6,957,758 and EP Patent No. 386, 031. Refining apparatus usually comprise two opposite refining discs rotatable in relation to each other, where usually one refining disc is rotatable, a so called rotor, and one refining disc is non-rotatable, a so called stator, but in some refining apparatus both refining discs are rotatably arranged. The refining discs in this type of refining apparatus are provided with replaceable refining segments which form the refining surfaces of the refining apparatus. The refining segments comprise bars and intermediate grooves. Refining occurs between the two refining surfaces which are held at a certain distance from each other, whereby a space, known as a refining gap, is provided between the refining surfaces. 
         [0003]    If the refining surfaces were to come in contact with each other during operation, this will result in a risk of a breakdown or at least result in wear of the refining surfaces, and thus a shortened operating performance. Furthermore, the degree of alignment between the refining surfaces has a crucial importance for the quality of the ground material. When the degree of alignment between the refining surfaces decreases, the quality of the refined material is deteriorated. A correct alignment between the refining surfaces is therefore of great importance. 
         [0004]    To obtain a correct alignment between the refining surfaces of the refining discs it is a prerequisite that the rotation axle, to which the rotor is attached, obtains correct alignment. To angle the axle in relation to the horizontal plane and the vertical plane, two alignment devices are used, which align the whole axle package, to which the axle and the rotor belongs. Such an alignment device according to known technology is described in more detail in the detailed description in connection with  FIGS. 1 to 6 . The alignment of the axle package, and thus of the axle and the rotor, is performed with approximately one-month intervals for a refining apparatus in operation. The adjustment of the axle along its own longitudinal axis is performed by means of another adjustment device which displaces the whole axle package in relation to the support in the direction of the longitudinal axis of the axle. This lengthwise adjustment of the axle package, and thus of the size of the refining gap, is performed several times per second, as the refining gap often must be reduced or increased because of the constant change in the quality of the material intended for refining, such as the amount of material per time unit. To obtain correct alignment between the refining surfaces of the refining discs, an alignment of the refining surfaces themselves in relation to the refining discs also takes place. An example of alignment of the refining surfaces themselves is given in British Patent No. 1,468,649. 
         [0005]    Certain problems exist, however, with the present alignment devices for aligning the refining disc of a refining apparatus, of which an example is described in detail in  FIGS. 4 to 6 . 
         [0006]    The requirement that the contact surface of the upper wedge-shaped member against the bearing housing must form different angles with the horizontal plane so that, at different settings of the axle package, they fully bear against the exterior surface of the bearing housing, results in the requirement that the upper wedge-shaped member must rotate in relation to the horizontal plane. This “tilting” of the upper wedge-shaped member results in a relatively large sideway play between the upper wedge-shaped member and the space in the support in which the upper wedge-shaped member is provided. This play results, however, in the upper wedge-shaped member easily jamming in its installation space in the support. Furthermore, the flat contact surface of the upper wedge-shaped member against the bearing housing and the flat contact surface of the bearing housing against the upper wedge-shaped member have a very even surface as these repeatedly slide in relation to each other, which poses high requirements on the machining of these flat surfaces. 
         [0007]    The requirement that the actuator of the alignment device must be placed on the side of the support which is facing away from the refining housing, so that the operator is able to control same, has led to a complicated construction of the alignment device, where the alignment by means of the alignment device includes many steps. This also results in a long distance between the securing point of the alignment device in the support and the lower wedge-shaped member, which leads to rendering the respective alignment device sensitive to temperature influence, and in addition the construction is not unresilient enough. 
         [0008]    The above-mentioned problems will appear more clearly from the detailed description, where the prior art is described in more detail. 
         [0009]    One of the objects of the present invention is thus to provide an alignment of the refining disc of a refining apparatus, which is reliable in service and straightforward to perform. 
       SUMMARY OF THE INVENTION 
       [0010]    In accordance with the present invention, this and other objects have now been realized by the invention of apparatus for aligning a refining disk in a refiner for disintegrating lignocellulose-containing material, the refiner including an axle package and a support for supporting the axle package with respect to the ground, the axle package including a rotatable axle attached to the refining disk and a bearing housing in which the rotatable axle is journalled, the bearing housing including bearings for the axle to facilitate rotation thereof, the apparatus comprising a first wedge member slidable along the support, a second wedge member disposed between the first wedge member and the bearing housing, the second wedge member slidable in a transverse direction to the slidable movement of the first wedge member, a controller for controlling the displacement of the first wedge member, and a support member for supporting the bearing housing, the support member being disposed between the second wedge member and the bearing housing, the bearing housing including a recess for accepting the support member, whereby the support member is adapted to engage the recess in the bearing housing, the support member having a convex contact surface for engagement with the recess in the bearing housing, the convex contact surface being displaceable with respect to the surface of the recess in the bearing housing. Preferably, the apparatus includes a plate comprising a polymer material disposed between the support member and the second wedge member, thereby providing a sliding surface therebetween without the need for lubrication. In a preferred embodiment, the plate has a length corresponding to the length of the portion of the support member proximate to the second wedge member. 
         [0011]    In accordance with one embodiment of the apparatus of the present invention, the support member is secured to the bearing housing. 
         [0012]    In accordance with another embodiment of the apparatus of the present invention, the controller comprises an actuator disposed at one end of the support and the control axle extending from the actuator to the first wedge member, the control axle being rotatable about its longitudinal axis and being rotatably secured to the first wedge member whereby operation of the actuator causes rotation of the control axle, which causes displacement of the first wedge member, which causes transverse displacement of the second wedge member. In a preferred embodiment, the controller further comprises at least one controller bearing housing, the controller bearing housing being attached between the actuator and the first wedge member. In accordance with a preferred embodiment, the control axle comprises first and second sub-axle portions, and a shaft coupling for coupling together the first and second sub-axle portions, the at least one controller bearing housing being attached between the shaft coupling and the first wedge member, and the first sub-axle portion being attached to the first wedge member and journalled by the bearings at the at least one controller bearing housing. 
         [0013]    In accordance with one embodiment of the apparatus of the present invention, the control axle includes a threaded section for attaching the control axle to the first wedge member, and including an inner threaded member for engagement with the threaded section of the control axle and fixedly engaged to the first wedge member, the first wedge member being displaceable with respect to the control axle. In accordance with a preferred embodiment, the threaded section of the control axle and the inner threaded member comprise parts of a ball screw. 
         [0014]    In accordance with the present invention, a support for an axle package for a refining disc in a refiner for disintegrating lignocellulose-containing material has been invented, the axle package including a rotatable axle attached to the refining disc and a bearing housing in which the rotatable axle is journalled, the bearing housing including bearings for the axle to facilitate rotation thereof, the support comprising a pair of alignment devices for aligning the refining disc, at least one of the pair of alignment devices comprising the apparatus set forth above. 
         [0015]    In accordance with the present invention, refining apparatus for disintegrating and refining lignocellulose-containing material has been invented comprising a refining disc and an axle package for the refining disc including a rotatable axle attached to the refining disc and a bearing housing in which the rotatable axle is journalled, the bearing housing including bearings for the axle to facilitate rotation thereof, and a support as set forth above. 
         [0016]    With this device, the second wedge-shaped member, which is situated above the first wedge-shaped member, does not need to be rotatable in relation to the horizontal plane, whereby the problematic ‘tilting’ of the second wedge-shaped member does not occur, and said member can be installed in its installation space/its guide without lateral play, whereby the risk that said wedge-shaped member jams in its installation space in the support is eliminated. The requirement that the flat surfaces must be very even in surface does not exist any more, as the main displacement occurs between said convex and concave surface. 
         [0017]    As the bearing housing, via the surface of the complementary recess, rests on the convex contact surface, these are in contact with each other, and the displaceability of convex contact surface the support means in relation to the surface of the complementary recess of the bearing housing comprises that the convex contact surface is displaceable along the surface of the complementary recess while there is surface contact between them. The convex contact surface can advantageously move in all directions along with and in contact with the surface of the complementary recess. 
         [0018]    According to an advantageous embodiment of the device according to the present invention, the device comprises a plate in a polymer material which is provided between the support means and the second wedge-shaped member, whereby a sliding surface without the need for lubricating oil is obtained, and advantageously said plate in polymer material has an extent corresponding to basis of the support means which is facing the second member. Hereby, there is no longer a need for the complicated feed of lubricating oil to the contact surface of the upper wedge-shaped member against the bearing housing in prior art. 
         [0019]    According to a further advantageous embodiment of the device according to the present invention, the support means is secured to the bearing housing. This facilitates when mounting the bearing housing in the support. This securing does however not fixate the support means but allows the displacement of the support means in relation to the bearing housing. 
         [0020]    According to another advantageous embodiment of the device according to the present invention, the control device comprises an actuator, which is provided at one side of the support, the control device comprising a control axle which extends from the actuator to the first member, where the control axle is rotatable around its longitudinal axis and rotatably secured to the first member, that the first member is arranged to be displaced upon rotation of the control axle, and the actuator is arranged to control the rotation of the control axle. 
         [0021]    In accordance with the present invention, an alignment is provided which comprises a minimum number of steps. In principle, only a rotation of the actuator in one direction is needed for the alignment. By means of this device the distance between the fastening point of the device in the support and the first wedge-shaped member is radically reduced. In this way, a control is also achieved which is uncomplicated in its construction and requires a considerably less twisting moment upon alignment compared to prior art alignment devices. 
         [0022]    According to yet another advantageous embodiment of a device according to the present invention, the control device comprises at least one bearing housing with bearings by which the control axle is journalled, the bearing housing being fastened in the support between the first member and the actuator. In this way a short distance is obtained between the fastening point of the device in the support, which is the same as the fastening point of the bearing housing of the device in the support, and the first member. 
         [0023]    According to a further advantageous embodiment of the device according to the present invention, the control axle comprises two sub-axles which are coupled together by means of a shaft coupling which is part of the control device, where the bearing housing of the control device is fastened in the support between the shaft coupling and the first member, and the sub-axle which is secured to the first member is journalled by the bearing of the bearing housing. The shaft coupling allows the longitudinal axes of the sub-axles to be angled in relation to each other without having the sub-axles rotating around their longitudinal axis in relation to each other, i.e. they do not rotate in relation to each other in their rotation direction. 
         [0024]    According to another advantageous embodiment of the device according to the present invention, the control axle is secured to the first member by a threaded section provided on the control axle, which is in engagement with a means provided with an inner thread, which is fixedly secured in the first member, the first member being displaceable in relation to the control axle. Advantageously, the axle comprising the threaded section and the means are integral parts of a ball screw. By means of the ball screw, also called a roll screw, a securing mechanism free from play of the control axle in the first member is achieved. 
         [0025]    In accordance with the present invention, an operator can control the actuator manually. The control device of the device according to the present invention can advantageously also be connected to a control apparatus for controlling the alignment between the refining surfaces for the two opposite refining discs rotatable in relation to each other and included in a refining apparatus, where the material is disintegrated and refined in the refining gap between the refining surfaces, and the device of the present invention is advantageously arranged to automatically align the rotatable refining disc of the refining apparatus based on this control until a correct alignment is obtained between the refining surfaces, which can, for example, be achieved by the fact that the actuator of the control device is connected to the control apparatus, for example connected by means of a control unit arranged to control the actuator based on the results of the control by the control apparatus. The alignment between the refining surfaces is correct when the width of the refining gap is kept constant for every diameter for a complete revolution. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0026]    The present invention will now be described, for exemplary purposes, in more detail in by means of embodiments and with reference to the accompanying drawings in which: 
           [0027]      FIG. 1  is a side, elevational, cross-sectional, schematic view of a refining apparatus, equipped with alignment devices according to the prior art; 
           [0028]      FIG. 2  is a front, cross-sectional, schematic view of the refining apparatus in  FIG. 1 ; 
           [0029]      FIG. 3  is a side, elevational, cross-sectional schematic view of a support for supporting the axle package, equipped with alignment devices according to the prior art; 
           [0030]      FIG. 4  is a side, elevational, cross-sectional, schematic view of an alignment device according to the prior art; 
           [0031]      FIG. 5  is a side, elevational, cross-sectional view of a detail in  FIG. 4 ; 
           [0032]      FIG. 6  is a side, elevational, cross-sectional view of a portion of  FIG. 4 , shown along section a-A thereof; and 
           [0033]      FIG. 7  is a side, elevational, cross-sectional, schematic view of an embodiment of the device for aligning the refining disc of a refining apparatus according to the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0034]    Referring to the figures, in which like reference numerals refer to like elements thereof,  FIG. 1  shows in outline a refining apparatus, in the form of a so called CD-refiner (Conical Disc), in cross-section as seen from the side, for disintegration and refining of lignocellulose-containing material in a refining gap  101  between refining surfaces on two opposite refining discs,  102  and  103 , rotatable in relation to each other, in the form of a rotatable rotor  102  and a non-rotatable stator  103 . The refining discs,  102  and  103 , are provided in a refining housing  104  and the material for refining is fed to the refining gap  101  through an inlet  105 . The rotor  102  is a part of what is called an axle package  106  and this axle package  106  comprises a rotatable axle  107 , the rotor  102  being attached to one of the ends of the axle  107 . The axle  107  is brought into rotation by a suitable drive (not shown). The axle  107  is supported by a rear bearing  108 , an intermediate bearing  109  and a front bearing  110 . All the bearings are arranged in a bearing housing  111  through which the axle  107  extends. The bearing housing  111  is in its turn arranged in a support  112 . To obtain a correct alignment between the refining surfaces of the refining discs,  102  and  103 , it is a prerequisite that the axle  107 , and thereby the rotor  102 , first obtains a correct alignment. To adjust the alignment of the bearing housing and the axle  107 , two alignment devices are used, of which only one alignment device  113  may be seen in  FIG. 1 . This alignment device  113  is described in more detail in connection with  FIGS. 4 to 6 . 
         [0035]      FIG. 2  shows a schematic front view of the refining apparatus in  FIG. 1 , in cross-section, where the bearing housing  111  is installed in the support  112 . Here, both alignment devices,  113  and  213 , are shown, as well as the manner in which they are placed in the support  112 . The bearing housing  111  is cylindrical with a substantially circular cross-section. Where the bearing housing  111  abuts against the alignment devices,  113  and  213 , the bearing housing  111  has flat surfaces which have been provided by milling. 
         [0036]    Returning to  FIG. 1 , the front part  114  of the bearing housing  111 , which is adjacent to the refining housing  104 , is supported by respective alignment device  113  while the rear part  115  of the bearing housing  111  is directly supported by the support  112 . The alignment devices  113  adjust the alignment of the axle  107  by respectively raising and lowering the front part  114  of the bearing housing  111  and/or displacing the front part  114  of the bearing housing  111  sideways, while the position of the rear part  115  is kept unchanged. 
         [0037]      FIG. 3  shows a support  201 , without the axle package mounted, and shows one of the alignment devices  202  installed in the lower part of the support  201 , and the front part of the bearing housing is supported by a support means  204 , which is a part of the alignment device  202 , and the rear part of the bearing housing rests on a lower rear portion  205  of the support  201 , and the bearing housing is supported at the top in principle by two retaining means,  206  and  207 , arranged in the upper part of the support. The bearing housing is supported in the corresponding manner on the other side of its symmetry line by the second alignment device (not shown). The support  201  rests on a ground surface  208 . 
         [0038]      FIG. 4  shows an alignment device according to the prior art, which is arranged in a support  301  in which the bearing housing is mounted and by which support the axle package is supported. The bearing housing is supported at the base by a support means  302 , which is a part of the alignment device, and by a lower part  303  of the support  301 . The first support means  302  is vertically slidable, while the second support means  303  is stationary. The first support means  302  is in the form of an upper wedge-shaped member  302  and this member  302  is movably arranged in a space  304  in the support  301 . In the same space  304  a pad  305 , in the form of a lower wedge-shaped member  305 , is arranged and rests on the bottom of space  304 . The lower member  305  is horizontally slidable. A bearing housing washer  306 , which is ring-shaped when seen from above, rests on the upper surface of the lower member  305 . On this bearing housing washer  306  a bearing washer  307  rests, which when seen from above is also ring-shaped. The bearing housing washer  306  and the bearing washer  307  are displaceable in relation to each other, and the bearing housing washer  306  is usually made of a hard material, such as stainless steel, while the bearing washer  307  is made from a softer material, such as bronze. The upper member  302  rests on the bearing washer  307 . The inner walls of the space  304  prevent the lateral displacement of the upper wedge-shaped member  302 . The contact surface of the upper member  302  against the bearing housing must, however, be able to form different angles with the horizontal plane to fully lie against the outer surface of the bearing housing at different adjustments of the axle package. The rotation of the upper member  302  in relation to the horizontal plane is achieved by bearing housing washer  306  and bearing washer  307 . This “tilting of the upper member  302  entails that there must be a relatively large sideway play between the side edges of the upper member  302  and the inner walls of the space  304 . However, this play entails that the upper member  302  can easily jam into space  304  when an alignment of the axle package is to be performed. Further, the flat contact surface of the upper wedge-shaped member  302  against the bearing housing and the flat contact surface of the bearing housing against the upper wedge-shaped member  302  must be very even as these repeatedly slide in relation to each other. 
         [0039]    In  FIG. 5  it can be seen that the bearing housing washer  306  and the bearing washer  307  are spherical in their design, and the contact surface of the bearing housing washer  306  against the bearing washer  307  is concave, while the contact surface of the bearing washer  30  against the bearing housing washer  306  is convex in cross-section. 
         [0040]    Returning to  FIG. 4 , the alignment device further includes a control device  300  arranged to push the lower member  305  to the left and right in  FIG. 3 . The control device  300  comprises a spacing screw  308  and a spacing tube  309  in which the spacing screw is provided, and the first end of the spacing screw  308  is fixedly secured in the lower member  305 . The spacing screw  308  is hollow along its whole length and in its second end there is an inlet  310  arranged, through which inlet  310  lubricating oil is introduced to the longitudinal channel of the spacing screw  308 , whereupon the lubricating oil is led to the first end of the spacing screw  308  and thereby to a first vertical channel  311  in the lower member  305 . The lubricating oil is then led from the first vertical channel  311  to a second vertical channel  312  arranged in the upper member  302  through a lead-through device  313 , which is described in more detail in connection with  FIG. 6 . From the second vertical channel  312  the lubricating oil is then led out onto the contact surface of the upper member  302  against the bearing housing. A lubrication of the contact surface between the upper member  302  and the bearing housing has been necessary in order to maintain a low friction between them, because the upper member  302  and the bearing housing slide in relation to each other when the axle package, as has been described in the introduction, is displaced in relation to the support in a direction along the longitudinal axis of the axle during the frequently occurring adjustment of the size of the refining gap. The control device  300  also comprises a console  314  which is fixedly arranged in the support  301  and a nut locking  315  fixedly arranged in the console  314 . Further, the control device  300  comprises actuators,  316 ,  317  and  318 , which are those means operated by the operator in order to align the axle package. The actuators,  316 ,  317  and  318 , comprise an adjustment screw  316  with an exterior thread which is set against the spacing tube and is in threaded engagement with the nut locking  315 . There are furthermore two jamb nuts,  317  and  318 , belonging to the actuators,  316 ,  317  and  318 , which are in threaded engagement with the spacing screw  308 . These jamb nuts,  317  and  318 , are used for bracing the lower member  305  at the desired position, to eliminate play. The actuators,  316 ,  317  and  318 , are as can be seen arranged in the rear part of the support  301 . This is the case since it is not practically possible to arrange the actuators,  316 ,  317  and  318 , in the front part of the support  301 , i.e. the part which is adjacent to the refining housing, to the right of the lower member  305 , as an operator then would not be able to operate the actuators due to the narrow space between the front part of the support  301  and the refining housing. The consequence is a long distance between the fixing point of the alignment device in the support, which is at the nut locking  315 , and the lower member  305 , which entails that the alignment device is sensible for temperature influence and the construction is not rigid enough. 
         [0041]    To lower the upper member  302  in a vertical direction, the operator starts by loosening the jamb nuts,  317  and  318 , whereupon the operator turns the adjusting screw  316  so that it is displaced to the right in  FIG. 3 , or in a direction towards the refining housing, in relation to the support  301 . The adjustment nut  316  then pushes the spacing tube  309  so it also is displaced to the right in relation to the support  301 , and thereby pushes the lower member  305  to the right in the figure. The lower member  305  then also pulls the spacing screw  308  with it so that this is also displaced to the right. By displacement of the lower member  305  to the right, the bearing housing washer  306  and the bearing washer  307  are also displaced to the right, whereby the upper member  302  is lowered in a vertical direction. Finally the jamb nuts,  317  and  318 , are turned so that they are displaced in a direction towards the adjustment screw  316 , so that the lower member  305  is tightened against the spacing tube  309  by the displacement of the spacing screw  308  to the left in relation to the spacing tube  309 , and play is eliminated. 
         [0042]    To raise the upper member  302  in a vertical direction the operator also in this case starts by loosening the jamb nuts,  317  and  318 , whereupon the operator turns the adjusting screw  316  so that it is displaced to the left in  FIG. 3 , or in a direction away from the refining housing, in relation to the support  301 . A space arises between the adjustment screw and the spacing tube  309 . Thereafter the jamb nuts,  317  and  318 , are turned so they are displaced in a direction towards the adjustment screw  316 , whereby the spacing screw  308  is pulled to the left and thereby pulls the lower member  305  to the left, and the lower member  305  pushes the spacing tube to the left. Due to the fact that the lower member  305  is displaced to the left, the bearing housing washer  306  and the bearing washer  307  are also displaced to the left, whereby the upper member  302  is raised in a vertical direction. To raise the upper member  302  in a vertical direction, more operations than when lowering the same are thus required. 
         [0043]    Due to the fact that two such alignment devices are arranged in the support, as seen in  FIG. 2 , the front part of the axle, which is fastened to the rotor, can be laterally and/or vertically displaced. 
         [0044]      FIG. 6  shows a detailed view of the lead-through device  313  provided between the upper member  302  and the lower member  305 . The lead-through device  313  includes a channel  501 , which connects to the first vertical channel  311  in the lower member  305  and to the second vertical channel  312  in the upper member  302 . The lead-through device  313  is fastened in the upper member  302  with a screw  502  but is displaceable in relation to the lower member  305 . The lead-through device  313  further comprises a first O-ring seal  503  for the sealing between the lead-through device  313  and the lower member  305  and a second O-ring seal  504  for the sealing between the lead-through device  313  and the upper member  302 , so that the lubricating oil cannot leak out on its way to the upper member&#39;s  302  contact surface against the bearing housing. However, this need of lubricating oil implies a complicated construction comprising the lead-through device  313  and all of the channels, as described above, and also a lubricating oil source must be connected to the inlet  310  of the spacing screw  308 , and this lubricating oil source must be controlled and maintained. 
         [0045]      FIG. 7  shows an embodiment of the device for aligning the refining disc of a refining apparatus according to present invention, arranged in a support  701  intended to rest on a ground surface, where the bearing housing  702  of the axle package and the support  701  are only partially shown. In the same way as shown in  FIG. 2 , two such devices for aligning the refining disc are used, and the device according to the present invention is intended to be mounted on the corresponding places shown in  FIGS. 1 to 3 . The device comprises a first wedge-shaped member  703 , which is slidable, in relation to the support, in a direction along the ground surface, and a second wedge-shaped member  704  provided between the first wedge-shaped member  703  and the bearing housing  702  of the axle package, which second member  704  is slidable, in relation to the support, in a direction transverse to the sliding direction of the first member. When displaced in its sliding direction, the first member  703  is arranged to displace the second member  704  in its sliding direction. The first member has a contact surface  705  against the second member  704 , and the second member  704  has a contact surface  722  against the first member  703 , which contact surfaces,  705  and  722 , form an angle with the ground surface. During the displacement of the first member  703  to the right in the figure, i.e. towards the refining housing, the second member  704  sinks downwards in a vertical direction by the influence of gravity, and during displacement of the first member  703  to the left in the figure, i.e. away from the refining housing, the second member  704  is raised in a vertical direction, whereby the desired alignment can be achieved. 
         [0046]    The device comprises a control device for displacing the first member  703 , which control device comprises an actuator  711  arranged at the side of the support  701 , which is opposite the side of the support  701  adjacent to the refining hosing. The control device comprises a control axle,  712  and  713 , which extends from the actuator  711  to the first member  703 . The control axle,  712  and  713 , is rotatable around its longitudinal axis and comprises two sub-axles,  712  and  713 , which are coupled together by means of a shaft coupling  715 . The control axle,  712  and  713 , is by means of its first sub-axle  713 , rotatably secured to the first member  703  by a threaded section provided on the first sub-axle  713 , which section is in engagement with a means  716  with an inner thread which in its turn is fixedly secured to the first member  703  by means of an fastening flange  717 . The first sub-axle  713  including the threaded section and the means  716  with the inner thread are parts of a ball screw/roll screw. The first member  703  is arranged to be displaced upon rotation of the control axle,  712   713 , and is slidable in its sliding direction in relation to the control axle,  712  and  713 . To allow this relative displacement the first member  703  comprises a space  718  for the first sub-axle  713 , which has a sufficient extent in the sliding direction of the first member  703 . The rotation of the control axle,  712  and  713 , is operated by the actuator  711  which is fixated in the control axle,  712  and  713 . The only operation which is required for displacement of the first member  703  is thus a rotation of the actuator  711  which causes a rotation of the control axle,  712  and  713 , and thereby a displacement of the first member  703 . The control device comprises a bearing housing  714  with bearings by which the control axle  712 ,  713  is journalled by means of its first sub-axle  713 . The bearing housing  714  of the control device is fastened to the support  701  between the shaft coupling  715  and the first member  703 . At the actuator  711  there is arranged a nut locking  719  for locking the actuator  711 , and a deep groove ball bearing  720  arranged for journaling the outer end of the control axle,  712  and  713 . 
         [0047]    Further, the device comprises a support means  706  on which the bearing housing  702  is intended to rest. The support means  706  is provided between the second member  704  and the bearing housing  702  and is arranged to engage with a to the support means  706  complementary recess  707  of the bearing housing. The support means  706  has a convex contact surface  708  against the recess  707  of the bearing housing  702 , and the convex contact surface  708  of the support means  706  is displaceable in relation to the surface of the complementary recess  707  of the bearing housing  702 . The device comprises a plate  709  in a polymer material, in this embodiment a web-reinforced, polyester based thermoset plastic material, which plate  709  is provided between the support means  706  and the second wedge-shaped member  704 , whereby a sliding surface is achieved, so that the axle package, as described in the beginning, can be displaced in relation to the support  701  in a direction along the longitudinal axis of the axle, during the frequently occurring adjustment of the size of the refining gap, without the need for lubrication oil. Plate  709  has an extent which corresponds to the bases  710  of the support means  706 , which base is facing the second member  704 . To facilitate mounting of the bearing housing  702  in the support  701 , the support means  706  is secured to the bearing housing  702  by means of a fastening means  721 . This fastening means  721  is fastened to the support means  706  by means of spring means  722  to allow the displacement of the support means  706  in relation to the bearing housing  702 . 
         [0048]    Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.