Abstract:
A drive mechanism of a cylinder of a printing machine uses a drive motor. The cylinder and the drive motor can be moved relative to one another in an axial direction. A coupling, whose length can be varied in a linear direction by a given amount, and which has a lamella packet connected to flanges in a positive locking manner, is arranged between the drive motor and the cylinder.

Description:
FIELD OF THE INVENTION 
   The present invention is directed to a drive mechanism for a cylinder of a printing press. A coupling is arranged between the cylinder and a drive motor for the cylinder. 
   BACKGROUND OF THE INVENTION 
   A printing group is known from DE 44 30 693 A1. A forme cylinder is driven and its output is transmitted to the transfer cylinder via spur wheels. In one preferred embodiment, a journal of the forme cylinder, embodied as a rotor, is axially displaceable in the stator for adjusting the lateral register on the forme cylinder. In one preferred embodiment, the forme and transfer cylinders are driven in pairs. 
   EP 0 722 831 B1 also discloses a drive for a cylinder, wherein the cylinder, which is driven by a motor, is axially displaceably arranged for the purpose of adjusting the lateral register. A rotor, which is coaxially arranged on the journal of the cylinder, can be axially moved in the stator. 
   In DE 196 03 663 A1 a forme cylinder is displaceable in the circumferential direction in respect to the transfer cylinder via a gear and a helical gear. The forme cylinder, and the transfer cylinder acting together with it, can be driven in parallel by a motor. An inking system assigned to the forme cylinder can be driven by a spur wheel that is arranged on the journal of the forme cylinder. 
   EP 1 000 737 A1 discloses a drive mechanism for a cylinder sleeve via a shaft which can be axially clamped against a disk. An axial coupling, which will allow an axial relative movement, is provided between the drive motor and the sleeve. 
   Various embodiments of torsionally rigid compensation couplings are disclosed inter alia on pages 407 to 411 of “Taschenbuch für den Maschinenbau”, Mechanical Engineering Handbook, Dubbel, 15th ed. 
   DE 197 55 316 C2 discloses a drive mechanism for a cylinder by a drive motor via a gear and a “compensating coupling”. Further cylinders are individually driven by their own drive motors. Because of their closeness to their respective cylinders, the drive motors are arranged offset from each other. 
   An operational connection between a forme cylinder driven via a gear and a transfer cylinder is known from DE 25 53 768 B2. A releasable coupling is arranged between the cylinders for the purpose of selective release. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is directed to providing a drive mechanism for a cylinder. 
   In accordance with the present invention, this object is attained by providing a drive mechanism for a cylinder of a printing press by use of a drive motor. A coupling is arranged between the drive motor and the cylinder. The coupling allows axial movement between the cylinder and the drive motor. The coupling may be arranged exterior of a lubrication chamber and has at least one multi-disk packet that is connected by flanges. At least a first gear may be arranged between the drive motor and the coupling. A second cylinder can be driven from the first cylinder by the same drive motor through a second gear located between the coupling and the first cylinder. 
   The advantages to be gained by the present invention rest, in particular, in that a drive mechanism for axially movable cylinders is created, wherein play in the circumferential direction and a large production outlay is minimized. 
   A coupling, which is flexible in the cylinder axial direction, is arranged between the drive motor and the forme cylinder to make an axial relative movement between the cylinder, which, in particular, is a forme cylinder, and a drive motor driving the forme cylinder possible. In an advantageous embodiment, the coupling is designed as a torsionally rigid shaft coupling, but which is flexible or resilient in the axial direction, for example as an expansion or compensation coupling. The employment of a non-switchable, positively-connected multi-disk coupling is particularly advantageous, which coupling, in contrast to other positively-connected couplings, is almost free of play in the circumferential direction without requiring an extensive production outlay and which coupling simultaneously makes an axial position change of the coupling itself, i.e. an axial movement of the forme cylinder, possible. The coupling is embodied to be positively-connected in the axial direction, but flexible or resilient in its length, for example because of elastic or reversible deformation. 
   Driving via the coupling is advantageous, in particular also in case of an individual drive mechanism at the individually driven cylinders, but particularly at the forme cylinder, for the purpose of adjusting the lateral register. If the cylinders of a printing group are each individually driven by a drive motor, the circumferential register can be changed by the making of changes in the relative angular position of the drive motor, and the lateral register can be changed by the way of the axial displacement of the motor and cylinder, relative to each other. In an advantageous configuration, the drive motors are arranged coaxially in respect to the cylinder to be driven. 
   In the case of cylinders which are driven in groups, and in particular for cylinders driven in pairs, the arrangement of the drive motor via the coupling at the forme cylinder of a pair of cylinders being driven together is advantageous. Because of the drive mechanism being located at the forme cylinder, no movement of the drive motor need to take place when the transfer cylinder is in either of the print-on and print-off position, such as is sometimes the case when driving takes place directly on the transfer cylinder. A compromise, based on such pivot movements of the transfer cylinder in connection with the position of the drive motor and the engagement of the gear wheels when the drive motor is arranged at the transfer cylinder, can be omitted when driving the forme cylinder. In the other case, the latter can lead to broken teeth or can also lead, because of the play in the drive mechanism, to a reduction of the print quality. 
   If only the inking system and the transfer cylinder are embodied to be placed against each other or to be moved away from each other, a rigid coupling of the drive motor to a lateral frame can take place. However, in general it is of advantage, also in view of the print quality, to improve properties of running true by arranging a gear, in particular a reduction gear in the drive connection. 
   In one preferred embodiment of the present invention, the drive motor can be arranged directly axially aligned with respect to the forme cylinder, or with respect to the driven cylinder. In order to make possible an axial movement of the forme cylinder for adjusting the lateral register, the coupling, which is flexible in the axial direction, can be arranged between the forme cylinder journal and the drive motor. The embodiment of the drive motor with a gear arranged between the motor rotor and the journal of the cylinder, for example a planetary gear, is advantageous With respect to advantageous rpm ranges, in particular in the start-up phase. 
   An arrangement is advantageous in cases where sturdiness requires a helical gear for the force transfer, and wherein the pinion of the drive motor does not act directly on the spur wheel. In this case, a displacement of the circumferential register would take place at the same time as an axial movement of the forme cylinder if no additional precautions were taken. Precautions which can be taken include, for example, a simultaneous correction via the control device, which requires an outlay of control technology, or alternatively, a permissible relative movement of the journal toward the spur wheel of the forme cylinder which, however, requires guide devices, which cannot be produced, or only with a large outlay, without play in the circumferential direction. A coupling flexible in the axial direction can again be employed for the axial mobility of the forme cylinder. 
   It is advantageous in connection with the above-described embodiments of the drive mechanism of the forme cylinder in accordance with the present invention if an inking system that is assigned to the forme cylinder and, possibly also a dampening system, are driven by the same drive motor. This saves expenses and assures synchronization, provided the gearing conditions are correct. 
   To facilitate the exact rotation of the cylinder and rollers in connection with a common drive mechanism during production, a common flow direction of the drive moments from the drive motor to th e various units to be driven is particularly advantageous. In an advantageous embodiment of the present invention, this is achieved in that driving takes place from the forme cylinder to the transfer cylinder, and from the transfer cylinder to the inking system, i.e. serially. In this connection, a preferred embodiment is particularly economical in which the driving takes place from the transfer cylinder to the inking system via a gear wheel that is rotatably arranged on the journal of the forme cylinder. 
   If the inking system and the transfer cylinder are driven in parallel through the forme cylinder, the use of auxiliary runners in case of gear wheel trains, or the use of belt drives, which are as free of play as possible, is required for at least one of the two drive trains. 
   The steps of embodying a coupling which is torsionally rigid, but that is axially changeable in length, as well as providing for a defined direction of moment flow, are used for minimizing the play in the drive mechanism, and thus for improving the printing quality. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the present invention are represented in the drawings and will be described in greater detail in what follows. 
     Shown are in: 
       FIG. 1 , a first preferred embodiment of a drive mechanism of a cylinder in accordance with the present invention, 
       FIG. 2 , a side elevation view, partly in section of an example of a coupling which is flexible in the axial direction, in 
       FIG. 3 , a second preferred embodiment of a drive mechanism of a cylinder in accordance with the present invention, and with a second cylinder and an inking system, in 
       FIG. 4 , a third preferred embodiment of a drive mechanism of a cylinder in accordance with the present invention, and with a second cylinder and an inking system, and in 
       FIG. 5 , a fourth preferred embodiment of a drive mechanism of a cylinder in accordance with the present invention, and with a second cylinder and an inking system. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring initially to  FIG. 1 , there may be seen a first preferred embodiment of a drive mechanism of a cylinder in accordance with the present invention. A first cylinder  01 , for example a forme cylinder  01  of a printing press, in particular a rotary printing press, has on its end face a journal  04 , which is rotatably seated in a lateral frame, that is not represented. On its end away from cylinder  01  the journal  04  is in operative connection with a drive motor  07  via a coupling  06 . 
   In the first preferred embodiment shown in  FIG. 1 , the coupling  06  is configured as a coupling  06 , in particular as a non-switchable, positively-connected shaft coupling  06 , or as an expansion coupling  06 , which is coaxially connected, on its end facing away from the cylinder  01 , via a coupling shaft  08 , with a shaft  09  of the drive motor  07 . In a preferred embodiment, a gear  10 , in particular a reduction gear  10 , such as a planetary gear  10 , for example, is arranged between the drive motor  07  and the coupling  06 . This connection between the coupling shaft  08  and the motor shaft  09  can also be provided by a non-switchable coupling  11 , for example a claw coupling  11 . If deviations in the axial direction or positioning of the cylinder  01  and the drive motor  07  must be compensated for, the coupling  11  can also be embodied in the manner of a spiral-toothed coupling. 
   The non-switchable coupling  06  is embodied in such a way that a length L in the forme cylinder axial direction can be changed by an amount Δ L, preferably in both directions. In contrast to claw couplings or to couplings having pins or bolts engaging bores, the axially adjustable coupling  06  is embodied in such a way that, in the axial direction, there is no sliding movement between two parts which are acting together as stops in the circumferential direction. Instead, coupling  06  is torsionally rigid in the circumferential direction, while it can be deformed resiliently, or reversibly elastically in the axial direction. The elements constituting the coupling  06  are positively connected with each other in the axial and circumferential directions and therefore make possible, without a large manufacturing outlay, an almost play-free drive in the circumferential direction, and an axial movement of the cylinder  01  by changing the coupling length L. Since there is no relative movement between two surfaces which are used as opposite stops transversely to the movement direction, the coupling  06  is wear-resistant and is insensitive to soiling. 
   An example of such a coupling  06 , which is only schematically depicted in  FIGS. 1 ,  3 ,  4  and  5 , is represented in detail in FIG.  2 . At its respective ends, the coupling  06  has ring-shaped end flanges  12 ,  13  having continuous bores  14 ,  16 ,  17 ,  18 , which adjoin in the circumferential direction and which extend axially. An also ring-shaped center element  19 , or flange  19 , with bores  21 ,  22  is arranged between the two end flanges  12 ,  13 . A multi-disk packet  23 , or  24 , in particular with disks made of steel, and with bores  26 ,  27  is arranged between the center flange element  19  and each one of the end flanges  12 ,  13 , respectively. Each multi-disk packet  23 ,  24  is alternatingly fastened in the circumferential direction by the use of screws  28 ,  29  to the adjoining end flange  12 ,  13  and to the center flange element  19  in such a way that each multi-disk packet  23 ,  24  is alternatingly positively connected with the end flanges  12 , or  13  and with the center element or flange 19 . Spacer elements  30 , for example washers  30 , which allow an axial displacement, are respectively arranged in the area of the screws  28 ,  29 , between the pretensioned multi-disk packet  23 ,  24  and the flange  12 ,  13 ,  19 . The preferred multi-disk packets  23  and  24  preferably include disks made of steel, which assure a high degree of rigidity in the circumferential direction, i.e. in the plane of their surface and perpendicularly in respect to the axis of rotation of the cylinder  01 , and with circular disks of lesser thickness which have elastic, or spring properties in the axial direction. 
   Such a coupling  06  is also called a flexurally elastic, all-metal coupling, a diaphragm coupling, or also a ring coupling. 
   Because of this coupling configuration, and because of the rigidity of the disks, the coupling  06  is embodied to be torsionally rigid in the circumferential direction and to be positively connected. The alternating fastening of the multi-disk packets  23 ,  24  on the respective end flange  12 ,  13  and on the center element or flange  19  allows, in spite of the positive connection in the axial direction, and because of the spring action of the disks in the multi-disk packet  23 ,  24 , a reversible change of the length L of the coupling  06  by an amount Δ L, which change in length Δ L is a function of the dimensions of the coupling L. The force to be exerted, i.e. a springiness of the coupling  06  in the axial direction, is a function of the number of disks in the multi-disk packet  23 ,  24 . A torsion spring value of the torque in the coupling  06  is preferably greater than 10,000 Nm/°, in particular in the range between 10,000 and 20,000 Nm/°. 
   If lesser amounts of Δ L are required, and no axial offset needs to be compensated- for, the coupling  06  can be embodied with only one multi-disk packet  23 ,  24  and without a center element or flange  19 , in which case the multi-disk packet  23 ,  24  is fastened in the circumferential direction alternatingly on one and on the other end flange  12 ,  13 . 
   In the first preferred embodiment of  FIG. 1 , a second cylinder  31 , for example a transfer cylinder  31  or a counter-pressure cylinder  31 , which works together with the first or forme cylinder  01 , is driven by its own, second drive motor  33 . The operative connection between the second drive motor  33  and the journal  32  can also be provided by the use of non-switchable couplings  06 ,  11 , which are not specifically represented. In an advantageous embodiment, a gear  10  is here also arranged between the second drive motor  33  and the second cylinder  31 . 
   If, for example, the second cylinder  31  is embodied as a transfer cylinder  31 , it works together, forming a printing position during printing, with a further cylinder, for example with a further transfer cylinder, a steel cylinder or a satellite cylinder, which is not specifically represented in FIG.  1 . 
   If the second cylinder  31  is embodied as a counter-pressure cylinder  31 , it forms a printing position together with the first or forme cylinder  01 . 
   In both cases, a lateral displacement of the printed image, in relation to another printed image from another printing position, might possibly be required during printing, so that the first cylinder  01 , embodied as forme cylinder  01 , must be axially displaced by the amount Δ L. Preferably, this amount Δ L lies between 0 and ±4 mm, and in particular lies between 0 and ±2.5 mm, and is taken up by the change of the length L of the coupling  06  by this amount ±Δ L. The end of the coupling  06  facing away from the forme cylinder  01 , for example the end flange  13 , is arranged fixed in place with respect to an axial direction, particularly with respect to an axial direction of the first, forme cylinder  01 . By use of the arrangement of the coupling  06 , the associated drive motor  07  can be arranged fixed in place, or fixed on the frame, during an axial displacement of the cylinder  01 . 
   In a second preferred embodiment of the present invention, as seen in  FIG. 3 , in which like elements are denoted by the same reference numerals, driving by the drive motor  07  of the shaft  08 , which is connected with the coupling, does not take place coaxially, but instead takes place through a gear  35 , and in particular a reduction gear  35 , for example by use of a pinion gear  34  to a driven gear wheel  36  arranged on the shaft  08 . Here, too, the arrangement of the coupling  11  between the drive motor  07  and the pinion  34  is advantageous in view of a simple separation. It is additionally possible to place a planetary gear  10 , which is not specifically represented, before the drive motor  07 . 
   As represented in  FIG. 3 , it is possible to drive a second cylinder gear wheel  38 , which is arranged, fixed against relative rotation, on the journal  32  of the second cylinder  31 , via the coupling  06  from the first cylinder  01  via a gear drive  40 , for example by the use of a first cylinder gear wheel  37 , which is arranged, fixed against relative rotation, on the journal  04  of the first cylinder  01 . Helical gears on the pinion gear  34  and the driven gear wheel  36  are advantageous because of the now occurring greater load. The two cooperating gear wheels  37 ,  38  on the journals  04 ,  32 , and which constitute the gear drive  40 , are advantageously provided with straight teeth, because a relative axial movement of the two with respect to each other is made possible, in this way without a compensation in the circumferential register between cylinders  01  and  31  becoming necessary. The gear drive  40  is located axially spaced between the coupling  06  and the cylinders  01 ,  31 . In this way, the power is transferred as closely as possible to the respective barrel of the respective cylinder  01 ,  31 , which additionally improves the accuracy of the drive mechanism and the printing quality. 
   In a variation, an inking system  39  and possibly a dampening system  41 , which are specifically depicted are also driven by means of the drive motor  07 . In this case, driving with a defined moment flow is advantageous. 
   For this purpose, power is transferred from the first or forme cylinder  01  via the gear wheels  37 ,  38  to the second cylinder  31 , and from the second cylinder  31  via a gear train  42 ,  43 ,  44  to the inking system  39  and the possible dampening system  41 . In  FIG. 3  a further second cylinder gear wheel  42  is arranged, fixed against relative rotation, on the journal  32  of the second cylinder  31  for this purpose and, acting together with it, a further first cylinder gear wheel  43 , which is rotatable relative to the journal  04 , is arranged on the journal  04  of the first cylinder  01 . The further first cylinder gear wheel  43  meshes with an output gear wheel  44 , which constitutes the drive mechanism for the inking system  39  and for the possible dampening system  41 . The gear wheels  42 ,  43 ,  44 , which constitute the drive gear train for the inking system  39  and for the possible dampening system  41 , are embodied with straight teeth, so that an axial displacement of the first cylinder  01  does not lead to a relative change in the angular position between the first cylinder  01  and the second cylinder  31 , and the first cylinder  01  and the inking system  39  and the possible dampening system  41 . 
   The drive mechanism of the drive connection for the mutual and serial driving of the cylinders  01 ,  31  and the inking system  39  and the possible dampening system  41  represented in  FIG. 3  can also take place, in accordance with  FIG. 1 , by use of a drive motor  07  coaxially arranged in respect to the shaft  08 , or the cylinder  01 . This applies correspondingly to the arrangement of a gear  10 , such as a reduction gear, and possibly a non-switchable coupling  11 . 
   In a third preferred embodiment of the present invention, as depicted in  FIG. 4 , again in which like elements are denoted by the same reference numerals, power is transferred from the first cylinder  01  parallel to the second cylinder  31  and to the inking system  39  and to the possible dampening system  41 . So that a tooth flank change under changing loads is prevented, in spite of the lack of a definite direction of the moment flow, the first cylinder gear wheel  37 , which is situated on the journal  04  of the first cylinder  01 , is arranged together with a gear wheel  46 , for example an auxiliary gear wheel  46 . Power can be transferred via a further first cylinder gear wheel  47 , also arranged on the journal  04  of the first cylinder  01 , to the output gear wheel  44 , which is providing the driving of the inking system  39  and of the possible dampening system  41 . Driving of the coupling shaft  08  can take place in one of the ways mentioned above either coaxially in respect to the shaft  08 , or via a pinion  34 , which is not represented in FIG.  4 . This applies correspondingly to the arrangement of the gears  10 , or  35 , and possibly to a coupling  11 . 
   In a fourth preferred embodiment of the present invention, as seen in  FIG. 5 , the power transfer from the first cylinder  01  to the second cylinder  03  does not take place on the side of the coupling  06  facing the cylinder  01 , but instead takes place on the side of the coupling  06  facing away from cylinder  01 , and which is not movable in the axial direction. For this purpose, the driving connection, or the gear drive  40 , between the first cylinder  01  and the second cylinder  31  is not arranged between the coupling  06 , whose length L can be changed in the axial direction, and the first cylinder  01 , but on the side of the coupling  06  which is facing away from the first cylinder  01  and which side of coupling  06  is stationary. 
   For the purpose of saving space and of shortening the required length of the cylinder journals  04 ,  32 , it is possible to connect a ring gear wheel  49  which is arranged, for example, on a bushing  48  enclosing the coupling  06  and adjacent with the side of the coupling  06  that is facing away from the cylinder  01 . On the one side, this ring gear wheel  49  meshes with a second cylinder gear wheel  51 , which is connected, fixed against relative rotation, with the journal  32  of the second cylinder  31 , and also meshes with the pinion gear  34 . In comparison with  FIG. 3 , one drive level can be saved with this fourth preferred embodiment, and driving of the cylinders  01 ,  31  can take place from the drive motor  07  via a helical gear. The drive connection formed by the ring gear wheel  49  and the second cylinder gear wheel  51  is not located on the side of the coupling  06  facing the cylinder  01 , which is to be moved axially, but on the side of coupling  06  which is stationary in respect to an axial movement. 
   In the preferred embodiment in accordance with  FIG. 5 , it is possible to arrange the drive motor  07  coaxially in respect to the coupling shaft  08 , while doing without the pinion gear  34  wherein, however, what was said above applies to a possibly provided gear  10 , such as a reduction gear  10 . 
   As already explained in part, the partially represented planetary reduction gear  10 , arranged at the drive motor  07 , or between the drive motor  07  and the coupling shaft  08 , or between the second cylinder drive motor  33  and the cylinder  31 , is advantageous for all of the preferred embodiments, in particular for the embodiment variations having a drive motor  07  which is arranged coaxially in respect to the coupling shaft  08 . In this case, the reduction gears  10 ,  35  are preferably configured as single, encapsulated gears, which can contain a thin-bodied lubricant, in particular oil, in their interior. In the case of the drive connection between the two cylinders  01 ,  31 , this gear drive  40  can also be encapsulated in an advantageous embodiment. However, the coupling  06  is advantageously arranged not in the encapsulated spaces, but on the outside of it, and is therefore easily accessible. The latter is the case in particular in connection with the embodiment of the coupling  06  as an above-described diaphragm coupling. 
   The drive connections between the two cylinders  03 ,  31 , and/or between one of the cylinders  03 ,  31  and the inking system  39 , or possibly the dampening system  41 , can also be provided by toothed belts, taking into consideration the reversal of the circulating direction, or other positively connected drive connections. 
   The manner of operation of the drive mechanism of a cylinder  01 ,  31  in accordance with the present invention is as follows: 
   During operation, i.e. during set-up and production operations, the cylinder  01  and, depending on the configuration with it, the second cylinder  31 , and also the inking system  39 , or possibly the dampening system  41 , are all driven by the drive motor  07 . 
   If a correction of the lateral system, for example if a lateral displacement of the printed image, is required, the first or forme cylinder  01  is displaced in the axial direction by an amount Δ L by use of a drive mechanism, which is not specifically represented, and which is arranged preferably on the side of the cylinder  01  located opposite the depicted drive mechanism, without the drive motor  07  of the depicted drive mechanism also having to be displaced. The amount Δ L of the axial displacement of cylinder  01  is taken up by the coupling  06 , wherein the end of the coupling  06  remote from the cylinder  01  is fixed in place, and in particular is fixed in place in respect to the axial direction of the coupling  06 . The displacement does not cause a simultaneous displacement of the circumferential register. 
   A control, by use of an electronic shaft between the cylinders  01 ,  31 , as well as a mechanical readjustment of the circumferential register, can be omitted. 
   While preferred embodiments of a drive mechanism of a cylinder, in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example, the specific size of the drive motor, the type of printing press in which the cylinder is used, and the like could be made without departing from the true spirit and scope of the present invention, which is accordingly to be limited only by the following claims.