Bearing, unit for converting a flat substrate, and methods for mounting and removing a rotary tool

1. A bearing assembly for a converting machine, the bearing assembly comprising a first bearing configured to hold a first rotary conversion tool, and a second bearing configured to hold a second rotary conversion tool positioned underneath and cooperating with the first rotary conversion tool to convert a substrate passing between the first and second rotary conversion tools, the first and second rotary conversion tools having parallel longitudinal axes, the first bearing comprising:

a first end rolling bearing device engaging with an end of the first rotary conversion tool;

a second end rolling bearing device engaging with the end of the first rotary conversion tool and spaced apart in a longitudinal axis direction from the first end rolling bearing device;

at least one first intermediate rolling bearing device interposed between the first and second end rolling bearing devices, the at least one first intermediate rolling bearing device engaging with the end of the first rotary conversion tool; and

at least one first mechanical actuator positioned above the first rotary conversion tool and exerting a radial preload force in a first radial direction at the first intermediate rolling bearing device;

the second bearing comprising:

a second intermediate bearing positioned in the longitudinal axis direction between the first and second end rolling bearing devices, the second intermediate rolling bearing device engaging with an end of the second rotary conversion tool; and

a second mechanical actuator positioned under the second rotary conversion tool and exerting a second radial preload force in a second radial direction at the second intermediate rolling bearing device,

wherein the first mechanical actuator provides the first radial force such that the first radial force urges the first intermediate bearing in a linear direction opposite to the second radial direction of the second radial force provided by the second mechanical actuator,

wherein the first radial direction of the preload force is opposed to a direction of a radial reaction force on the first rotary conversion tool.

2. The bearing assembly according to claim 1 , wherein the at least one first mechanical actuator is configured to exert the radial preload force on an external ring of the at least one first intermediate rolling bearing device.

3. The bearing assembly according to claim 1 , wherein the at least one first mechanical actuator is configured to move an external ring of the at least one intermediate rolling bearing device radially.

4. The bearing assembly according to claim 1 , wherein the at least one first mechanical actuator comprises a control element configured to activate and deactivate the application of the radial preload force.

5. The bearing assembly according to claim 1 , wherein the at least one first mechanical actuator comprises a cylinder.

6. The bearing assembly according to claim 5 , wherein the cylinder comprises:

a chamber and a piston,

the piston having a first end configured to move in the chamber in the first radial direction with respect to an external ring of the at least one intermediate rolling bearing device, and

the piston having a second end fixed to the at least one intermediate rolling bearing device.

7. The bearing assembly according to claim 1 , wherein each of the end rolling bearing devices and the at least one intermediate rolling bearing device comprises an internal surface and an external ring,

wherein at least one internal surface of each of the end rolling bearing devices and the at least one intermediate rolling bearing device is formed by the external surface of the end of the first rotary conversion tool.

8. A conversion unit for converting a flat substrate, the conversion unit comprising the bearing assembly according to claim 1 .

9. The conversion unit according to claim 8 ,

wherein the at least one first mechanical actuator is configured to move upward the at least one intermediate rolling bearing device; and

wherein the second mechanical actuator is configured to move downward the at least one intermediate rolling bearing device.

10. A method for mounting a rotary conversion tool in a bearing assembly according to claim 1 , the method comprising:

inserting ends of the first rotary conversion tool into the end rolling bearing devices of the first bearing; and then

exerting the radial preload force at the at least one first intermediate rolling bearing device interposed between the end rolling bearing devices.

11. A method for removing a rotary conversion tool from the bearing assembly according to claim 1 , the method comprising:

deactivating application of the radial preload force at the at least one intermediate rolling bearing device interposed between the end rolling bearing devices; and

extracting the ends of the first rotary conversion tool from the bearings.