Hydrodynamically loaded web press with slipper bearing shoes

Abstract

A press mechanism for removing liquid from a traveling fibrous web such as a web of paper received from the fourdrinier section of a paper machine including a backing roll and a looped traveling belt forming a press nip with the roll with a plurality of shaped shoes extending the length of the roll and pressing the belt toward the nip with said shoes having a concave curved surface facing the belt and being pivotally supported so that a wedge of lubricating fluid builds up between each of the shoes and the belt to lubricate the shoes and to press the belt toward the nip. Means are provided for individually controlling the force with which the shoes are pressed toward the belt.

I claim as my invention: 
     
       1. A press mechanism for removing liquid from a traveling fibrous web comprising in combination, a press nip formed between first and second members for receiving a traveling web therebetween,   one of said members being a traveling flexible impervious belt,   .Iadd.the other of said members being a roll, .Iaddend.   force means engaging the outer surface of said belt including a sliding shoe having a smooth surface facing the belt with said surface extending transversely, across the belt and also extending in the direction of belt travel with means for pressing the shoe toward the belt with a predetermined force,   .Iadd.means for pivotally supporting said shoe about a pivotal axis extending transversely of the direction of belt travel, .Iaddend.   means for providing a film of lubricating fluid between the shoe and the belt, the leading edge of said shoe being relieved to form a hydraulic wedge of lubricating fluid between the shoe and belt,   .Iadd.said shoe surface being concave arcuately shaped so that a dewatering pressure extends along the full length of the shoe, .Iaddend.   and means for receiving liquid pressed from the web between said members.   
     
     
       2. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 and including .[.means for pivotally supporting said shoe about a pivotal axis extending transversely of the direction of belt travel.]. .Iadd.a housing enclosing said shoe with seals between the belt and housing to prevent the escape of said lubricating fluid. .Iaddend. 
     
     
       3. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 wherein the .[.other of said members is the outer surface of a rotatable.]. .Iadd.radius of curvature of said shoe surface is substantially the same as said .Iaddend.roll. 
     
     
       4. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 and including a plurality of sequentially located additional shoes in engagement with the outer surface of the belt each similarly constructed and providing additional areas of pressure. 
     
     
       5. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 4 wherein each of the shoes is provided with a pivotal support and has a relieved leading edge shaped to form a wedge of lubricant between the shoe and the belt, and the structure includes an enclosure for retaining lubricating fluid for the shoes and enclosing said shoes. 
     
     
       6. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 4 and including means for individually controlling the force applied to each of the shoes so sequentially increasing forces can be applied to the belt. 
     
     
       7. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 4 wherein each of said shoes is provided with a fluid pressure means for forcing the shoe toward the belt. 
     
     
       8. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 7 wherein said fluid pressure means includes a piston and cylinder and a controllable fluid pressure line leads to each of the cylinders for individually controlling the forces applied to the shoes to force them toward the belt. 
     
     
       9. A press mechanism for removing liquid from a traveling .[.fibrius.]. .Iadd.fibrous .Iaddend.web comprising in combination, a rotatable roll,   a looped flexible, impervious belt wrapped over an arc of the roll and forming a pressure nip therewith for receiving a traveling web,   a felt traveling through the nip with the web,   a plurality of .Iadd.sequential .Iaddend.slipper bearing shoes .Iadd.each .Iaddend.having a smooth lower surface extending transversely across the roll against the outer surface of the belt,   means for delivering a lubricant between the belt and shoes,   means for pivotally supporting the shoes with said shoes being arcuately concave shaped with a relieved leading edge to form a film of fluid therebetween so that the pressure on the belt is transmitted through the wedge of fluid formed between .[.the.]. .Iadd.each .Iaddend.shoe and the belt,   and controllable fluid pressure means for pressing the shoes toward the belt.   
     
     
       10. A press mechanism for removing liquid from a traveling fibrous web comprising in combination, a press nip formed between first and second members for receiving a traveling fibrous web therebetween,   one of said members being a traveling flexible impervious belt,   the other of said members being a cylindrical roll with the belt wrapped over an arc of the roll,   force means engaging the outer surface of said belt including a sliding shoe having a concave surface .Iadd.along the full length of the shoe so that a dewatering pressure extends along the full length of the concave surface, said surface being .Iaddend.of substantially the radius of said roll extending transversely and also in the direction of belt travel with means for pressing the shoe toward the belt,   .Iadd.means supporting said shoe accommodating movement of the shoe about an axis parallel to the axis of the roll, .Iaddend.   means for providing lubrication between the shoe and the belt,   and means for receiving liquid pressed from the web between the roll and belt. .Iadd.   
     
     
       11.  A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 wherein said shoe is axially continuous for substantially the width of said belt. .Iaddend. .Iadd.12. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 11 wherein said shoe is flexible over its entire length. .Iaddend. .Iadd.13. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 11 wherein said means for pressing the shoe toward the belt includes a hydraulic fluid cylinder with a piston movable therein pivotally connected to the shoe with said cylinder and said piston being continuous for the width of the belt. .Iaddend. .Iadd.14. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 13 wherein said piston is flexible over its entire length. .Iaddend. .Iadd.15. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 including means for providing a linear tension in the belt for increasing the force of the belt against the web to increase the dewatering pressure. .Iaddend. .Iadd.16. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 wherein said means for receiving liquid includes first and second felts arranged so that the web is carried between them between the belt and roll. .Iaddend. .Iadd.17. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 including a second belt parallel to the first positioned to engage the opposite side of the roll to be in opposing relationship to the shoe, and second force means engaging the outer surface of said second belt including a second sliding shoe having an arcuately shaped concave smooth surface facing the second belt with said surface extending transversely across the second belt and also extending in the direction of belt travel with means for pressing the second shoe toward the belt with a predetermined force and means for providing a film of lubricating fluid between the second shoe and the second belt with said second shoe surface being concave arcuate shaped so that a dewatering pressure extends along the full length of the second shoe. .Iaddend. .Iadd.18. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 1 wherein said roll is an open roll with said means for receiving liquid pressed from the web being in the form of a felt and the web carried between the felt and the belt. .Iaddend. .Iadd.19. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 9 wherein the first shoe is of longer length to obtain a reduced unit pressure between the belt and first shoe and then between the belt and a succeeding shoe. .Iaddend. .Iadd.20. A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 9 wherein said controllable fluid pressure means includes a hydraulic fluid pressure chamber with a piston pivotally connected to the shoe for each of the shoes with the chambers being of increasing width in the direction of belt movement so that the pressure applied to the web through the shoes increases. .Iaddend.