EP0754548B1 - Bearing for a cylinder of a printing machine - Google Patents

Abstract

There is a print element (5) with a print supply or delivery (6) integrated in a machine frame (4). There is bearing bore which is mounted in a circle sector adjoining a bearing (1') and when biased by pressure fixes the bearing and when the pressure is relaxed releases the bearing for a swivel movement. The print element is an elastic hollow body coupled to a source of pressurised medium. The print element is pneumatically or hydraulically operable. A piezoelectric print element can be connected to an adjustable voltage source.

Description

The invention relates to a bearing arrangement for a printing press cylinder, in particular for an offset printing machine with bearings on both sides in a starting and stopping eccentric Cylinder journal.

DE 2 636 555 C2 discloses a backlash-free cylinder bearing for printing presses which has loading devices for producing a bending bridge which acts on the journal bearing. The loading devices are arranged in parallel in the longitudinal bores of the machine wall running parallel to the cylinder axis on both sides at an angle to the resulting bearing force and are thus formed by a metal body as a bending bridge. This bending bridge acts in a linear manner on the bearing bush, which leads to so-called "feed eaters" in a known manner. In order to prevent a possible risk of breakage (material fatigue due to deformation / load change) on the bending bridge (machine wall), in a further embodiment, a slot which is separate from the machine wall is arranged at the end of the longitudinal bore of the loading device. In this embodiment too, the bending bridge is partially deformed by the linear load of the bearing body.

According to US A 3,786,749 is a bearing arrangement for a printing press cylinder known with an inner and an outer eccentric. There is a in the outer eccentric Arranged pressure element which is pivotally movable with the eccentric.

The object of the invention is to provide a noticeably reduced bearing arrangement for a printing press cylinder, which ensures the required break resistance without deforming the sliding or rolling bearing. This is solved by the training features of claims 1 and 5.
The bearing arrangement has at least one pressure element arranged in the region of the bearing bore, preferably an elastic pressure element, which acts on the bearing from a position integrated into the machine frame in a defined circular sector. The bearing arrangement can accommodate a plain bearing or a roller bearing in an eccentric bearing. A surface force increases the security against breakage in the printing press cylinder bearing. The applied surface load acts on the plain bearing or rolling bearing without any dangerous deformation, since the bearing play can be influenced in the form of a surface. During the printing operation, the bearing arrangement is fixed in position by the surface pressure of the pressurized pressure element; when the pressure is on or pressure off, the pressure element is depressurized. The pressure element can be acted upon pneumatically or with a fluid, for example hydraulically. In a further embodiment, the application can also be carried out using a piezo material. The pressure element is preferably elastic, at least in the area that applies a surface pressure to the bearing. The bearing arrangement is not limited to a pressure element. Rather, several pressure elements can enclose the bearing arrangement in a sector of a circle.

Fig. 1

eine Druckzylinderanordnung (schematisch),

Fig. 2

eine Lageranordnung mit Druckelement.

Fig. 3

ein Druckelement in Einbaulage (Schnitt A-A)

The invention will be explained in more detail using an exemplary embodiment. Show:

Fig. 1

a pressure cylinder arrangement (schematic),

Fig. 2

a bearing arrangement with a pressure element.

Fig. 3

one pressure element in installation position (section AA)

In a printing press there is a plate cylinder 2 with a blanket cylinder in a printing unit 1 adjacent and the blanket cylinder 1 is with a printing cylinder 3rd arranged adjacent. The cylinders 1, 2, 3 have cylinder journals that are in the frame side a bearing 1 'for the blanket cylinder 1, a bearing 2' for the plate cylinder 2 and a bearing 3 'for the printing cylinder 3 are added. In the exemplary embodiment for the impression cylinder 3, the bearing 1 'marked with detail X for the blanket cylinder 1 considered as a bearing arrangement. In a machine frame 4 is in one Bore 7 inserted the bearing 1 '. The bearing 1 'represents an eccentric bearing arrangement which houses a bearing bush. Since the storage 1 'for functional reasons must be pivotable, there is an annular gap between the bore 7 and the bearing 1 '(not shown) arranged. A pressure element 5 is approximately concentric in a circular sector arranged for storage 1 '. For this purpose, the pressure element 5 is in a recess in the machine frame 4 recorded and acts on the storage 1 '. In the present For example, the pressure element 5 has a pressure supply / discharge 6 Further development, a sensor can be arranged on the annular gap, which is controlled by a machine control for measuring bearing play, operating temperature, relative movement of the External bearing activates or stops the pressure element 5. In the exemplary embodiment, this is Pressure element 5 is a crescent-shaped hollow body which is connected to the pressure supply / discharge 6 with a pressure medium source, e.g. a pneumatic device or Hydraulic device, is coupled. The hollow body is made of an elastic plastic. Alternatively, the pressure element 5 can also be made of a piezoelectric, preferably piezoceramic, Material. The pressure element 5 is made use of inverse piezoceramic effect activated. The pressure element 5 is in this training Connected to an adjustable voltage source in terms of circuitry an electrical field causes a change in dimension of the piezoelectric material of the pressure element 5. By applying e.g. a DC voltage increases the piezoelectric material, so that the pressure element 5 fixes the bearing without play. Lies no electric field, the bearing can be swiveled.

The mode of action is as follows:
In the bore 7, the bearing 1 'and in this a cylinder journal is used. The annular gap between the bore 7 and the bearing 1 'also extends to the pressure element 5. The bearing 1' can be pivoted in the annular gap for the adjusting movement “pressure on” or the parking movement “pressure off” of the blanket cylinder 1. For the printing operation, the printing element 5 is activated via the machine control. The pressure element is in the bearing 1 'in a circular sector of max. 180 ° applied a surface pressure, which fixes the bearing 1 'frictionally during printing. The arrangement of the pressure element 5 to the bearing 1 'is to be carried out in such a way that the resulting force undergoes the smallest possible change in direction (in a defined angular range) during printing operation. This ensures the exact fixation of the bearing 1 'in the bore 7 even in the event of changing external loads.

Reference list

1

Blanket cylinder

1'

camp

2nd

Plate cylinder

2 '

camp

3rd

Impression cylinder

3 '

camp

4th

Machine frame

5

Pressure element

6

Pressure supply / discharge

7

drilling

X

detail

Claims (5)

1. Bearing arrangement for a printing press cylinder, particularly for an offset printing press, with cylinder trunnions mounted on both sides in eccentrics which can be thrown on and off and a pressure element with means for pressure feed and pressure relief,
   characterised in that in a press frame (4) having an integral bearing bore (7), at least one pressure element (5) is arranged in fixed position with a pressure feed/pressure relief in a circular sector concentrically to a bearing (1',2',3'), wherein on subjecting the pressure element (5) to pressure, the bearing (1',2',3') can be fixed and on relieving the pressure on the pressure element (5), the bearing (1',2',3') is free for a swivel movement.
2. Bearing arrangement according to Claim 1,
   characterised in that the pressure element (5) is an elastic hollow body which is linked with a source of pressure medium.
3. Bearing arrangement according to Claim 2,
   characterised in that the pressure element (5) is pneumatically actuatable.
4. Bearing arrangement according to Claim 2,
   characterised in that pressure element (5) can be actuated with a fluid.
5. Bearing arrangement for a printing press cylinder, particularly for an offset printing press with cylinder trunnions mounted on both sides in eccentrics which can be thrown on and off, characterised in that in a press frame (4) integrated with a bearing bore (7) at least one piezoelectric pressing element (5) is connected in circuit with an adjustable source of voltage and arranged in a circular sector concentrically adjacent to a bearing (1',2',3'), which under the action of an electrical field, fixes the bearing (1',2',3') and in the absence of the electric field, frees the bearing (1',2',3') for a swivel movement.

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