Pneumatic zone-controlled deflection compensation for roll

1 . A deflection compensated roll, comprising:

a shaft;

a shell configured to rotate around the shaft;

one or more loading units between the shaft and the shell configured to adjust a nip load profile, wherein the one or more loading units comprise

a pressure chamber;

a seal configured to seal the pressure chamber with pressurized gas; and

a flexible mounting configured to mount the seal flexibly on the shaft;

wherein the seal comprises, a body, a restrictor, and means for distributing pressurized gas to the restrictor;

the restrictor has a surface facing a seal gap, an entirety of the surface is spaced from a mating surface of the shell to define the seal gap between the restrictor and the mating surface; and

the restrictor is configured to flow the pressurized gas through the restrictor into the seal gap, wherein the pressurized gas is configured to keep the restrictor from contacting the mating surface.

2 . The deflection compensated roll according to claim 1 , wherein the seal has a first and a second mode, wherein the seal is configured

in the first mode to allow the pressurized gas from the seal to flow into the pressure chamber and/or an ambient, when the seal gap has higher pressure than the pressure chamber; and

in the second mode to allow gas from the pressure chamber to leak through the seal gap to the ambient and/or to allow gas from the seal flow to the ambient, when the seal gap has lower pressure than the pressure chamber.

3 . The deflection compensated roll according to claim 1 , wherein the means for distributing pressurized gas comprises at least one distribution groove, channel, or hole in the body or in the restrictor.

4 . The deflection compensated roll according to claim 3 , wherein

each of the at least one distribution groove, channel, or hole is configured to be connected to an own pressure supply; or

at least two distribution grooves, channels, or holes are configured to be connected to a common pressure supply.

5 . The deflection compensated roll according to claim 1 , wherein the restrictor is a porous material element.

6 . The deflection compensated roll according to claim 1 , wherein the flexible mounting comprises at least one of: a guide element and a loading part.

7 . The deflection compensated roll according to claim 6 , wherein the guide element and the loading part are in one element.

8 . The deflection compensated roll according to claim 6 , wherein the guide element comprises at least one of the following: a flexure, a flexing element, a compliant mechanism, a slide, and/or an aerostatic bearing guide.

9 . The deflection compensated roll according to claim 8 , wherein the aerostatic bearing guide is configured to allow the seal to float and be preloaded against the shell by the loading part.

10 . The deflection compensated roll according to claim 6 , wherein the loading part comprises at least one of the following: an actuator, a pressurized hose, a pressurized bladder, and/or a spring.

11 . The deflection compensated roll according to claim 1 , wherein the deflection compensated roll is configured to compensate deflection by adjusting supply and/or discharge of the pressurized gas to and/or from at least one of the following: the seal, the pressure chamber, and/or the flexible mounting.

12 . The deflection compensated roll according to claim 1 , wherein the one or more loading units comprise

multiple loading units configured to share a common seal dividing multiple pressure chambers;

multiple loading units each configured to have an individual seal dividing the multiple pressure chambers;

a single loading unit; or

a combination of a single large loading unit and multiple smaller loading units.

13 . A method for controlling a nip load with a deflection compensated roll, wherein the deflection compensated roll comprises:

a shaft;

a shell configured to rotate around the shaft;

one or more loading units between the shaft and the shell, wherein the loading unit comprising a pressure chamber, a seal, and a flexible mounting, wherein the seal comprises, a body, a restrictor, and means for distributing pressurized gas to the restrictor, wherein the restrictor has a surface facing a seal gap, an entirety of the surface is spaced from a mating surface of the shell to define the seal gap between the restrictor and the mating surface, and wherein the restrictor is configured to flow the pressurized gas through the restrictor into the seal gap, wherein the method comprises:

adjusting a nip load profile by the one or more loading units by

sealing the pressure chamber with pressurized gas by the seal; and

mounting the seal flexibly on the shaft.