Patent Publication Number: US-2015059359-A1

Title: Rotary body of a printing press

Description:
This application claims the priority of German Patent Document No. DE 10 2013 109 536.4, filed Sep. 2, 2013, the disclosure of which is expressly incorporated by reference herein. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The invention relates to a rotary body of a printing press such as a printing press cylinder or a printing press roller. The invention furthermore relates to a method for operating such a rotary body of a printing press. 
     In a printing press, a multitude of rotary bodies are installed such as, for example, printing press rollers and printing press cylinders. The printing press cylinders can, for example, be transfer cylinders, forme cylinders, counter cylinders or the cylinders for various printing methods such as, for example, offset printing method and/or intaglio printing method and flexographic printing methods and the like. The rollers of a printing press can, for example, be paper guide rollers, ink transfer rollers of an inking couple and dampening solution transfer rollers of a dampening unit or a cooling roller for reducing the temperature of the substrate. These printing press cylinders as well as printing press rollers can be installed both in reel-fed printing presses and also in sheet-fed printing presses. The rotary bodies of a printing press can heat up during operation. In order to counteract such heating-up of rotary bodies of a printing press, it is known from practice to temperature control the rotary bodies of a printing press with the help of water cooling. Temperature controlling a rotary body of a printing press with the help of water cooling however is relatively complex since the cooling water on the one hand has to be conducted into the rotary body of a printing press and on the other hand conducted out of the same. To this end, rotary joints for water are required, in the region of which leakage can form. A further disadvantage of water cooling with justifiable expenditure is that the rotary bodies of a printing press can only be uniformly temperature controlled over the entire surface with the help of water cooling. 
     Starting out from this, the present invention is based on the object of creating a new type of rotary body for a printing press and a method for operating the same. 
     According to the invention, the outer surface is temperature controllable via at least one Peltier element integrated in the rotary body of a printing press, namely coolable and/or heatable. The temperature controlling of the outer surface of a rotary body of a printing press with the help of at least one Peltier element integrated in the rotary body of a printing press has the advantage that leakages of rotary joints for water can be avoided. 
     Preferentially, multiple Peltier elements are integrated in the rotary body, wherein preferentially surface portions of the outer surface are individually temperature controllable via each of the Peltier elements or Peltier elements which are connected into groups. By integrating multiple Peltier elements in the rotary body of a printing press, the surface of the same can be temperature controlled in portions. Different surface portions can be individually temperature controlled with little effort, as a result of which a defined temperature profile can be set along the surface of the rotary body of a printing press. 
     According to a further advantageous development, multiple Peltier elements next to one another and behind one another are integrated in the rotary body of a printing press in the axial direction and the circumferential direction, wherein preferentially a surface portion of the outer surface is individually temperature controllable via each of the Peltier elements. This arrangement of the Peltier elements in the axial direction next to one another and the circumferential direction one behind the other is preferred in order to set a defined temperature profile in the axial direction as well as in the circumferential direction along the surface of the rotary body of a printing press. 
     Preferentially, thermal insulating elements are arranged between Peltier elements that are adjacent or positioned next to one another and behind one another. Through the arrangement of the insulating elements between adjacent Peltier elements, interactions between the Peltier elements can be excluded in order to make possible an even more temperature controlling of the surface of the rotary body of a printing press in portions. 
     According to an alternative advantageous further development, at least one temperature sensor is integrated in the rotary body of a printing press, with which a temperature actual value can be collected in order to regulate the or each Peltier element dependent on a deviation of the temperature actual value from a temperature set point value. By way of the or each temperature sensor, a temperature closed-loop control can be established in the respective surface portions of the rotary body of a printing press. 
     According to an alternative advantageous further development, the rotary body of a printing press comprises an inner tube which, on an outer face in a radial cross-section, is formed circularly or at least triangularly or as a rounded polygon with at least three straight edges (rounded polygon) and on this outer face, carries the Peltier elements. The rotary body of a printing press furthermore comprises an outer tube which radially surrounds the inner tube at least in sections on an inner face which corresponds to the outer face of the inner tube and is formed circularly or at least triangularly or as a rounded polygon and which on an outer face provides the outer surface. Supply lines for the Peltier elements run within the inner tube. This configuration of the rotary body of a printing press is advantageous for a simple design realization. 
     Preferentially, the inner tube of the rotary body of a printing press is ventilated. Alternatively, the outer surface is additionally water temperature controlled, wherein the water temperature control serves for a basic temperature control and the temperature control via the or each Peltier element serves for precision temperature control. 
     Preferred further developments of the invention are obtained from the subclaims and from the following description. Exemplary embodiments of the invention are explained in more detail with the help of the drawings without being restricted to this. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a radial cross-section through an exemplary embodiment of a rotary body according to the invention; 
         FIG. 2  is a top view of the rotary body of a printing press according to the invention without an outer tube of the same; and 
         FIG. 3  is a detail of the rotary body of a printing press according to the invention in the region of a shaft of the same mounted on a printing press frame. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The invention relates to a rotary body of a printing press, such as for example a reel-fed printing press or a sheet-fed printing press. The rotary body of a printing press according to the invention can be a cylinder of a printing press or a roller of a printing press. 
     In particular when the rotary body of a printing press is designed as a cylinder of a printing press, the same can be a forme cylinder, a transfer cylinder or even an impression cylinder. In particular when the rotary body of a printing press is designed as a printing press roller, the same can be a paper guide roller, an ink transfer roller of an inking couple as well as a dampening solution transfer roller of a dampening unit or a cooling roller for reducing the temperature of the substrate. 
     These examples of printing press cylinders and printing press rollers are purely exemplary in nature. The invention is not restricted to these application cases but can also be employed on other rotary bodies. 
       FIGS. 1 to 3  show different views of an exemplary embodiment of a rotary body of a printing press  10  according to the invention, wherein the rotary body of a printing press  10  comprises a shaft  11 , which is rotatably mounted with lateral shaft portions  12  on a printing press frame  14  via bearings  13 . 
     The rotary body of a printing press  10  has an outer surface  15 , which seen in radial cross-section is contoured circularly. This outer surface  15  of the rotary body of a printing press  10  according to the invention is temperature controllable, namely coolable and/or heatable via at least one Peltier element  16  integrated in the rotary body of a printing press  10 , wherein in the rotary body of a printing press  10  preferentially multiple such Peltier elements  16  are integrated, and wherein preferentially via each of the Peltier elements  16  or via Peltier elements  16  connected into groups a section of the outer surface  15  of the rotary body of a printing press  10  each can be individually temperature controlled. 
     In the axial direction and/or in the circumferential direction of the rotary body of a printing press  10 , multiple Peltier elements  16  are integrated in the rotary body of a printing press  10  next to one another and/or behind one another. In the shown exemplary embodiment, eight Peltier elements each are positioned, seen in the circumferential direction of the rotary body of a printing press  10 , behind one another and three Peltier elements  16  each are positioned, seen in the axial direction of the rotary body of a printing press  10 , next to one another, so that accordingly altogether 24 Peltier element  16  are integrated in the rotary body of a printing press  10 . 
     It is pointed out that the above number of the Peltier elements  16 , which in the circumferential direction of the rotary body of a printing press  10  are positioned one behind the other and the above number of the Peltier elements  16  positioned in the axial direction of the same next to one another, are purely exemplary in nature. 
     The number of the Peltier elements  16  which are positioned in the axial direction next to one another is arbitrary and depends in particular on the axial construction length of the rotary body of a printing press  10  and on the number of the surface portions to be individually temperature controlled in the axial direction of the same. 
     The number of the Peltier elements  16  each positioned in the circumferential direction one behind the other preferentially amounts to at least two, preferentially three, in particular between eight and sixteen. 
     As is evident from  FIGS. 1 and 2 , a thermal insulating element  17  is arranged between each of the Peltier elements  16  positioned in the circumferential direction behind one another and between each of the Peltier elements  16  positioned in the axial direction next to one another, in order to avoid interaction between the individual Peltier elements  16  and in this way ensures an optimum individual temperature control of the individual surface portions of the rotary body of a printing press  10 . 
     Temperature controlling of the rotary body of a printing press  10  with the help of the Peltier elements  16  can on the one hand take place in the sense of a control and on the other hand in the sense of a closed-loop control. In particular when temperature controlling of the outer surface  15  of the rotary body of a printing press  10  takes place in the sense of closed-loop control, preferentially multiple temperature sensors  18  are integrated in the rotary body of a printing press  10 , wherein preferentially each surface portion to be individually temperature controlled is assigned an individual temperature sensor  18 , with the help of which on the respective surface portion of the outer surface  15  of the rotary body of a printing press  10  an individual temperature actual value can be collected. 
     Alternatively, at least one contactlessly operating temperature sensor  18  for collecting the temperature actual value for the entire outer surface  15  or surface portions of the rotary body of a printing press  10  can be employed. 
     Dependent on a deviation of the respective temperature actual value from a corresponding temperature set point value, the Peltier element  16  assigned to the respective surface portion is individually closed-loop controlled, i.e., in order to set an individual temperature in the region of the respective surface portion of the outer surface  15  of the rotary body of a printing press  10 . 
     In particular when no individual temperature controlling of the rotary body of a printing press  10  on surface portions of its outer surface  15  is required, all individual Peltier elements  16  shown in  FIGS. 1 and 2  can be interconnected and jointly activated. 
     It is possible, furthermore, to interconnect and jointly activate or closed-loop control individual Peltier elements  16  even upon individual temperature controlling of the rotary body of a printing press on surface portions of its outer surface  15 . In the variant shown in  FIGS. 1 and 2 , in which 24 Peltier elements  16  are integrated in the rotary body of a printing press  10 , for example two Peltier elements  16  each adjacent in the circumferential direction can be interconnected and jointly activated in order to thus individually temperature control, for example, 12 surface portions of the outer surface  15  via the 24 Peltier elements  16 . Peltier elements  16  which are adjacent in the circumferential direction and/or Peltier elements  16  which are adjacent in the axial direction can be interconnected and jointly activated. 
     In a particularly advantageous design embodiment of the rotary body of a printing press  10  according to the invention, the same comprises an inner tube  19 , which on an outer surface  20  of the same seen in the radial cross-section of  FIG. 1 , is circular or at least triangular, and in the exemplary embodiment of  FIG. 1  is octagonal, or is a rounded polygon in order to form, as seen in the circumferential direction, face portions on which at least one Peltier element  16  each can then be accommodated. 
     The rotary body of a printing press  10  furthermore comprises an outer tube  21 , which radially surrounds the inner tube  19  on the outside at least in portions, namely at least in the region in which the Peltier elements  16  are positioned, wherein the outer tube  21  on an inner face  22  is contoured corresponding to the inner tube  19  on the outer face  20  of the latter, circularly or at least triangularly or as a rounded polygon with at least three flat faces, and in the exemplary embodiment of  FIG. 1  octagonally, i.e., has the identical number of corners of the outer face  20  of the inner tube  19 . 
     The outer face of the outer tube  21  forms the outer surface  15  of the rotary body of a printing press  10  to be temperature controlled. 
     Through this configuration of the rotary body of a printing press  10 , the Peltier elements  16  on the one hand can be optimally arranged on the inner tube  19  of the rotary body of a printing press  10 , and in addition to this an optimum contact of the same to the outer tube  21  of the rotary body of a printing press  10  can be ensured. The Peltier elements  16  are preferentially glued to the inner tube  19  and/or the outer tube  21  via a heat-conducting adhesive. 
     Preferentially, supply lines  24  for the Peltier elements  16  run within the inner tube  19  and thus in a channel  23  defined by the inner tube  19 , wherein these supply lines  24  for the Peltier elements  16  are combined into a cable  25  and starting out from this cable  25  lead in the radial direction to the individual Peltier elements  16 . 
     By way of a rotary joint  26 , for example in the form of a slip ring assembly, the cable  25  carrying the supply lines  24  can be introduced starting out from the printing press frame  14  into the inner tube  19  of the rotary body of a printing press  10 . 
     According to an advantageous further development of the invention it is provided to subject the inner tube  19  of the rotary body of a printing press  10  to ventilation with an airstream, in order to thus subject the interior space  23  of the inner tube  19  permanently to a through flow of air and in this way discharge heat from the rotary body of a printing press  10  via this air flow. 
     By way of a suitable rotary joint  27  for the air flow, an air stream can be introduced into the interior space  23  of the inner tube  19  and be discharged from the same, wherein the air flow through the interior space  23  of the inner tube  19  can be generated via a blower  28 . 
     Alternatively or even additionally, the flow of an air stream through the inner tube  19  can also be realized through the mere rotation of the rotary body of a printing press. In this case, an inner face  29  of the inner tube  19  preferentially has a groove or a spiral with a defined pitch which, with rotating rotary body  10 , then generates the air flow through the channel  23  defined by the inner tube  19 . 
     According to a further advantageous further development of the invention it can be provided that the rotary body of a printing press  10  is temperature controlled not only via the Peltier elements  16  but additionally via water cooling. In this case, a basic temperature control of the outer surface  15  of the rotary body of a printing press  10  can then take place via the water cooling and precision temperature control of the outer surface  15  via the Peltier elements  16 . 
     In an alternative configuration, the rotary body of a printing press  10  can be embodied without a separate inner tube  19 . In this variant, a Peltier element  16  is attached to an inner face  22  of the outer tube with a circular or at least triangular or rounded polygonal cross-section with a preferentially heat-conducting adhesive or other connecting methods. It speaks for itself that mounting a rotary body  10  embodied in this way would have to take place on the outer face of the outer tube  21  or the inner face  22  of the outer tube  21  or on a separate if appropriate mechanically dismountable roller journal which is not shown in the figures. 
     The present invention furthermore relates to a method for operating such a rotary body  10 , wherein the outer surface  15  of the same is temperature controlled via the Peltier elements  16  integrated in the rotary body of a printing press  10 , namely cooled and/or heated. 
     As already explained, the Peltier element  16  in this case can be interconnected and uniformly activated in this case for the uniform temperature controlling of the rotary body of a printing press  10  on its outer surface  15 . On the other hand, it is possible for establishing an individual temperature control of individual surface portions of the outer surface  15  of the rotary body of a printing press  10  to individually or by groups activate all individual Peltier elements  16  or also Peltier elements  16  connected into groups, preferentially closed-loop controlled individually or by groups. 
     It is thus possible, despite different loads on the outer surface  15  or effects on the outer surface  15  of the rotary body of a printing press  10 , such as different pressures, inhomogeneous color profile or use of part-width webs, to realize a uniform temperature profile on the outer surface  15  of the rotary body of a printing press  10 . Furthermore, the temperature profile with inhomogeneous loading, such as for example during the use of part-width webs or strands, can be adjusted to an inhomogeneous, and therefore, optimum temperature profile since it suits the requirement on the outer surface  15  of the rotary body of a printing press  10 . 
     In addition to this, in the case of inhomogeneous loading or influencing of the rotary body of a printing press  10  through uneven temperature performance of the Peltier elements  16  activated or closed-loop controlled individually and/or by groups, an arbitrary, i.e., even or uneven, temperature profile on the outer surface  15  of the rotary body of a printing press in the circumferential or the axial direction can be realized so that this temperature profile can always be optimally adapted to the respective requirements. 
     LIST OF REFERENCE NUMBERS 
     
         
         
           
               10  Rotary body 
               11  Shaft 
               12  Shaft section 
               13  Bearing 
               14  Printing press frame 
               15  Outer surface 
               16  Peltier element 
               17  Insulating element 
               18  Temperature sensor 
               19  Inner tube 
               20  Outer face 
               21  Outer tube 
               22  Inner face 
               23  Interior space/channel 
               24  Supply line 
               25  Cable 
               26  Rotary joint 
               27  Rotary joint 
               28  Blower 
               29  Inner face 
           
         
       
    
     The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.