Compliant pressure roller with uniform nip pressure
View Patent ↗A compliant pressure roller ( 10 ) for creating uniform pressure at a nip ( 42 ) has a stationary inner core ( 12 ). A plurality of shoes ( 14 ) is pivotally mounted to the stationary inner core. Non-magnetic dividers ( 16 ) create a plurality of annular chambers ( 18 ) and one shoe occupies one of the chambers. A magneto-rheological fluid fills each of the chambers and a plurality of magnetic field generators ( 13 ) changes a magnetic field in each of the chambers. A thin, rotatable shell ( 24 ) surrounds the plurality of chambers, shoes, and stationary inner core.
1. A compliant pressure roller for creating uniform pressure at a nip comprising:
a stationary inner core;
a plurality of shoes pivotally mounted to said stationary inner core;
non-magnetic dividers creating a plurality of annular chambers wherein each of said shoes occupies one of said chambers;
a magneto-rheological fluid filling each of said chambers;
a plurality of magnetic field generators for changing a magnetic field in each of said chambers; and
a thin, rotatable shell surrounding said plurality of chambers, shoes, and stationary inner core.
2. A compliant pressure roller as in claim 1 wherein each of said magnetic field generators is in each of said shoes.
3. A compliant pressure roller as in claim 1 wherein each of said magnetic field generators is in said stationary inner core.
4. A compliant pressure roller as in claim 1 wherein said magneto-rheological fluid is a heat transfer agent.
5. A compliant pressure roller as in claim 1 wherein said shoes are spring loaded to said stationary inner core.
6. A compliant pressure roller as in claim 1 wherein said thin, rotatable shell is metal.
7. A compliant pressure roller as in claim 1 wherein each of said magnetic field generators are individually adjustable to compensate for deformation in said thin, rotatable shell.
8. A compliant pressure roller as in claim 1 wherein each of said field generators are individually adjustable to compensate for variations in thickness of a web.
9. A compliant pressure roller as in claim 1 wherein a hydrodynamic force on said magneto-rheological fluid created by rotation of said thin, rotatable shell compensates for deformation in said shell.
10. A compliant pressure roller as in claim 1 wherein a deformation detector is located in each of said shoes.
11. A compliant pressure roller as in claim 1 wherein an eddy current detector detects deformation in said thin, rotatable shell and provides a deformation signal to a microprocessor which adjusts at least one of said magnetic field generators.
12. A compliant pressure roller as in claim 1 wherein a laser detector detects deformation in said thin, rotatable shell and provides a deformation signal to a microprocessor which adjusts at least one of said magnetic field generators.
13. A compliant pressure roller as in claim 1 wherein a face of a each of said pluralities of shoes creates a converging zone with an inner surface of said thin, rotatable shell.
14. A compliant pressure roller as in claim 1 wherein a curvature of a face of each of said pluralities of shoes is greater than a curvature of an inner surface of said thin, rotatable shell in order to create a converging zone.
15. A compliant pressure roller as in claim 1 wherein said plurality of shoes are eccentrically mounted.
16. A compliant pressure roller for creating uniform pressure at a nip comprising:
a stationary inner core;
a plurality of shoes pivotally mounted to said stationary inner core;
non-magnetic dividers creating a plurality of annular chambers wherein each of said shoes occupies one of said chambers;
a magneto-rheological fluid filling each of said chambers;
a plurality of magnetic field generators for changing a magnetic field in each of said chambers;
a thin, metal, rotatable shell surrounding said plurality of chambers, shoes, and stationary inner core;
wherein each of said magnetic field generators are individually adjustable to compensate for deformation in said rotatable shell; and
wherein a hydrodynamic force on said magneto-rheological fluid created by rotation of said shell compensates for deformation in said shell.
17. A compliant pressure roller as in claim 16 wherein each of said magnetic field generators is in each of said shoes.
18. A compliant pressure roller as in claim 16 wherein said magneto-rheological fluid is a heat transfer agent.
19. A compliant pressure roller as in claim 16 wherein said shoes are spring loaded to said stationary inner core.
20. A compliant pressure roller as in claim 16 wherein a deformation detector detects deformation in said shell and adjusts at least one of said magnetic generators to compensate for said deformation.
21. A compliant pressure roller as in claim 20 wherein an eddy current detector detects deformation in said shell and provides a deformation signal to a microprocessor which adjusts at least one of said magnetic field generators.
22. A compliant pressure roller as in claim 20 wherein a laser detector detects deformation in said thin, rotatable shell and provides a deformation signal to a microprocessor which adjusts at least one of said magnetic field generators.
23. A compliant pressure roller for creating uniform pressure comprising:
a stationary inner core;
a plurality of shoes pivotally mounted to said stationary inner core;
non-magnetic dividers creating a plurality of annular chambers wherein each of said shoes occupies one of said chambers;
a magneto-rheological fluid filling each of said chambers;
a plurality of magnetic field generators for changing a magnetic field in each of said chambers;
a thin, rotatable shell surrounding said plurality of chambers, shoes, and stationary inner core;
at least one detector for detecting deformation in said thin, rotatable shell;
a microprocessor for processing information on shell deformation; and
adjusting at least one of said magnetic field generators to compensate for shell deformation.