US3276102A

US3276102A - Adjustable crown roll

Info

Publication number: US3276102A
Application number: US339998A
Authority: US
Inventors: Edgar J Justus
Original assignee: Beloit Corp
Current assignee: Beloit Corp
Priority date: 1964-01-24
Filing date: 1964-01-24
Publication date: 1966-10-04
Anticipated expiration: 1983-10-04
Also published as: FI46278C; DE1461066B2; FR1412267A; NL6500922A; ES305227A1; NO120103B; FI46278B; GB1059366A; DE1461066A1

Description

Filed Jan. 24, 1964 E. J- JUSTUS ADJUSTABLE CROWN ROLL Oct. 4, 1966 3,276,102

-6 Sheets-Sheet 1 INVENTOR,

Oct. 4, 1966 E. J. JUSTUS ADJUSTABLE CROWN ROLL 6 Sheets-Sheet 2 Filed Jan. 24, 1964 I N VENTOR.

E. J. JUSTUS ADJUSTABLE CROWN ROLL Oct. 4, 1966 6 Sheets-Sheet 3 INVENTOR.

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Filed Jan. 24, 1964 TTENQNEYS Och 1966 E- J. JUSTUS 3,276,102

I ADJUSTABLE CROWN ROLL Filed Jan. 24, 1964 6 Sheets-Sheet 4 I NVE NTOR A TT( )1 Oct. 4, 1966 E. J. JUSTUS I ADJUSTABLE CROWN ROLL 6 Sheets-Sheer,

Filed Jan. 24, 1964 I N VENTOR.

BY MZ/M v AT IY RNISYS United States Patent 3,276,102 ADJUSTABLE CROWN ROLL Edgar J. Justus, Beloit, Wis., assignor to Beloit Corporation, Beloit, Wis., a corporation of Wisconsin Filed Jan. 24, 1964, Ser. No. 339,998 14 Claims. (Cl. 29-116) This application is a continuation-in-part of application Serial No. 52,456, now Patent No. 3,119,324, filed August 29, 1960.

The present invention relates to improvements in rolls and particularly to an improved roll structure for obtaining controlled nip pressure between a roll couple.

In roll couples forming pressure nips therebetween roll deflection occurs when loads are applied to the rolls to obtain pressures in the nip. Various arrangements have been employed to obtain either a controlled or a uniform nip load along the length of the nip, Crowned rolls are usually satisfactory only for one predetermined nip load and other mechanical and hydraulic nip loading devices have not proven entirely satisfactory. The provision of uniform nip pressure is particularly important in papermakin-g machinery, for example, wherein the uniform treatment of a web of paper across its width is essential to obtaining a uniform and satisfactory product, and in a Wet press, for example, uniform extraction of water is dependent upon unifiorm nip load, and in a satisfactory ma chine provisions must be made for varying the overall nip load.

An object of the present invention is to provide an improved roll structure which utilizes a cylindrical rol-l shell supported and loaded on its inner surface by a shoe means opposite the nip which is particularly satisfactory in obtaining uniform nip pressures over a range of overall nip loads and is capable of continuous high speed long openating life without rapid Wear and Without requiring frequent part replacement or servicing attention.

A further object of the invention is to provide an improved roll assembly capable of controlled deflection for obtaining a uniform nip load which is relatively inexpensive to construct and avoids disadvantages of the structures heretofore available.

A still further object of the invention is to provide an improved roll assembly having a roll shell with an inner supporting shoe means wherein superior lubrication is maintained between the shoe means and the shell, and the provision of extensive fluid seals or close manufacturing tolerances is avoided.

A still further object of the invention is to provide an improved control deflection roll having an outer roll shell supported on its inner surface opposite its nip area having features which make it particularly satisfactory for use in high speed papermaking machines at the nip loads required and which provides advances over structures heretofore available that make it practical for commercial use in :such environments.

The mechanism contemplates providing a ro l] assembly including an outer elongate tubular cylindrical roll shell with a non-rotatable shaft means extending through the shell, means supporting the shaft means, bearing means between the roll shell and shaft means for positioning the roll shell, an elongate limber shoe means having an outer surface co-extensive with the length of the roll shell and being in axially continuous supporting engagement with the inner surface of the roll shell opposite a nip formed with another roll with said surface being rigidly shaped to build up a supporting film of lubricating fluid during relative notation of the roll shell from fluid within the shell, a controlled fluid pressure loading means mounted on the shaft means applying radially outwardly directed forces to said shoe means along the length thereof so that 3,276,102 Patented Oct. 4, 1966 a continuous nip loading force is maintained within the roll shell, and means pivotally supporting said shoe means for pivotal movement relative to the inner surfiace of the roll shell to conform to the pressure of the fluid lubricating film between the surface of the shoe means and roll shell.

Other objects, advantages and features of the invention will become more apparent with the teaching of the principles thereof in connection with the disclosure of the preferred embodiment in the specification, claims and drawings, in which: 7

FIGURE 1 is a vertical sectional view taken through the axis of a controlled deflect-ion 1 011 constructed and operating in accordance with the principles of the present invention, showing one end of the roll;

FIGURE 2 is a vertical sectional view taken substantially on line IIII of FIGURE 1;

FIGURE 3 is a smaller sectional view, similar to FIG- URE 1, illustrating the arrangement along the length of the D011;

FIGURE 4 is an enlarged detailed fragmentary view showing the end plate at the end of the fluid pressure channel;

FIGURE 5 is a fragmentary sectional view illustratin the structure of the bearing shoe; I

FIGURE 6 is a fragmentary side eleuational view of the pivot bar;

FIGURE 7 is an end elevational view of the pivot bar;

FIGURE 8 is a fragmentary end elevational view showing an arrangement for two pressure rolls; 7

FIGURE 9 is a fragmentary vertical sectional view showing an arrangement whereby the controlled deflection roll is driven;

FIGURE 10 is a schematic showing of the fluid pressure circuits and control for the controlled deflection roll;

and

FIGURE 11 is a graph showing pressure relationships for changing nip pressures and roll deflection.

As shown on the drawings:

FIGURES 13 show a controlled deflection roll assembly 11 which operates in a roll couple with a second roll in the manner illustrated in FIGURE 8. The roll assembly includes an elongate cylindrical hollow roll shell 12 with a core or inner stationary shaft means 13 extending therethrough. The roll shell 12 is supported opposite the nip by a shoe means 14 which slidingly engages the inner surface of the roll shell 12.

The shoe 14 is supported for applying a force to the roll shell by an elongate axially extending piston means or pivot bar 15. The shoe 14 is pivotally supported so as to tiltably conform to the inner surface of the shell 12 and the film of supporting lubricating fluid which builds up between the shoe 14 and inner surface of the shell 12. For providing the pivotal support an elongate pivot pin 16 is positioned between the pivot bar 15 and the shoe 14.

The inner non-rotatable shaft 13 has a hollow center 17, being substantially tubular in shape within the roll shell 12, and has radial openings such as 18 for accommodating tubing. At the ends of the shaft are shaft ends 19 which are centrally hollow to accommodate tubing, and bearing lubricating passages 20 extend axially into the shaft ends 19. r

For supporting the roll assembly the shaft is supported at the ends on self-aligning bearings having parts 21 and 22 and a surrounding support 23 which is suitably mounted in a bracket such as shown in FIGURE 8. The bearing parts 21 and 22. are prevented from rotating relatively to thereby hold the shaft 13 against rotation by a threaded pin 24.

In the roll mounting of FIGURE 8, the upper controlled deflection roll 11 is supported on a bracket 25 secured to a mounting bracket 26 on a machine frame 27. The controlled deflection roll 11 forms a nip with a lower roll 28 which is suitably supported and may be loaded at its ends by suitable mechanism such as that shown schematically by the arrowed line 29 to control the overall nip pressure. An arrangement of this type provides a press couple for a wet press of a paper machine and while the features of the invention are particularly well adapted to use in paper machinery for presses, calenders and the like it will be appreciated that they may be employed in other environments.

As shown in FIGURE 1, for holding the roll shell 12 in place and maintaining it in alignment with its mating roll, bearing rings 30 are bolted to the ends of the roll shell and are supported on bearings 31 on the ends 19 of the shaft. These may be Torrington type bearings secured by a threaded bearing ring 34. Bolted to the bearing ring 35 is an outer ring 32 carrying a sheave 33 for driving the roll shell 12 for finishing the outer surface thereof in preparation for use. The ring 32 has an inwardly extending flange for preventing the escape of lubricant from the bearing 31. The lubricant is supplied through the passage 20 and excess lubricant passes centrifugally out through the passages 35 into the interior of the roll shell and lubricant deflectors 36 bolted to the end of the shaft 13 clear the ends of the oil passages 35 within the shell so that the oil can escape and be returned through the return line as will be later described.

As shown in FIGURES 1-3, the inner surface 37 of the roll shell 12 is smooth and the outer surface 38, FIGURES 2 and is formed to a radius 40 the same as the radius of the inner surface 37 of the shell 12. The leading end of the shoe 14 is removed to provide either a curved or, as shown, a flat surface 39 providing a lubricant collecting wedge shaped area which builds up a film of supporting fluid between the outer surface 38 of the shoe and the inner surface 37 of the shell. The pivotal support of the shoe 14 permits it to accommodate the building up of this supporting layer of fluid and permits the equalization of the pressure of the fluid over the outer surface 38 of the shoe. With this arrangement the sliding engagement between the shoe 14 and the shell 12 can occur at high speeds required by modern papermaking machinery without undue wear and without the generation of undue heat. Thus, because of the rigid outer shape of the shoe with its leading relieved nose surface 39, and because of the pivotal support of the shoe 14 successful high speed continued support can be achieved.

Another factor which contributes materially to the successful relationship between the shoe 14 and shell 12 is the provision of a shoe 14 with a continuous elongate outer surface 38 which is co-extensive with the length of the shell. By providing a continuous outer surface no concentrations of stress occur and no bending of the shell occurs at unsupported locations. Also there are no nonuniformities along the length of the shell with respect to the generation of heat due to the friction and uniform support is maintained along the entire length of the nip. The shoe 14 is relatively limber so that it can bend with bending of the roll while maintaining a uniform nip pressure and is preferably formed of a chilled casting cold worked 35% before machining. While a preferred arrangement is illustrated, it will be understood that the shoe could be formed in sections, with each section being independent but abutting each other so that the outer surface 38 would still provide a continuous support for the shell. Thus, reference herein to a continuous supporting surface in an axial direction encompasses the surface provided by a one-piece limber beam or by a beam formed in a number of pieces with the pieces closely abutting each other in an axial direction.

For providing the pivotal support for the shoe 14, an axially extending arcuate recess 41 is provided on the inner surface of the shoe, and a similar recess 42, shown in FIGURES 6 and 7, is provided in the pivot bar 15. These recesses 41 and 42 are formed to the radius of the 4 pin 16, which may be in sections along its length. The pivot pin is held at the recesses due to the forces between the pivot bar 15 and the shoe 16.

The pivot bar has a recess 43 extending on all surfaces near its base for receiving an O-ring to provide a seal for the liquid in an axially extending channel 44 in which the pivot bar 15 slides.

The channel 44 is rectangular in shape and is cut for the full length of the shaft 13. The channel can easily be milled and its ends are closed by end plates 45. The

inner surfaces of the end plates are relieved at 45a substantially in line with the surface 49 of the core with the relieved portion preventing the pin 16 from working axially out of the grooves. The end plates are conveniently bolted in place by bolts extending into tapped holes in the shaft.

The shaft 13 is formed with a planar surface 49 on each side of the channel 44, and the shoe 14 is wider than the width of the channel 44 so as to have surfaces 48 on each side of the channel which seat on the shaft surface 49 when pressure is relieved from the channel 44, but which clear the surface 49 during normal operation.

For delivering fluid under pressure to the channel pressure lines 47 lead to the channel from a main pressure line 47a.

The channel is shown as formed in sections with dividers 50 between each of the sections and with the pivot bar 15 similarly formed in sections and the sections abutting the dividers 50. The dividers are conveniently formed by rectangular blocks which are set into the channel and held in place by bolts tapped into the top of the blocks with a sealing material around the edge of the blocks, With this arrangement fluid at different pressures can be directed to the different compartments into which the channel is divided by the dividers 50, although usually for maintaining uniform nip pressure the compartments will be interconnected as shown. Fluid pressure is preferably provided by hydraulic oil delivered from a controlled output pump.

For maintaining lubricating fluid such as oil within the inner surface of the shell 12 a lubricating line 51 directs a stream of oil against the inner surface of the shell ahead of the shoe 14. This oil spreads out and provides the built-up layer of lubricating film which forms between the shoe and the shell. Excess oil is returned through an oil return line 52, FIGURES 1 and 3; for aiding in returning the oil, scoops 53 are mounted at the ends of the shaft adjacent the ends of the shoe 14 at the leading edge thereof. These scoops gather up the excess oil that spreads out beyond the end of the shoe and feed it to the return lines 52.

Thus, in operation, lubricating fluid is continually supplied to the inner surface of the shell 12 through the lubricating supply line 51, and a film of lubricating oil builds up in the wedge shaped relieved leading edge 39 of the shoe 14 to build up a supporting film between the outer surface 38 of the shoe and the inner surface 37 of the roll shell 12. Excess oil is returned through the return lines 52. The shoe 14 provides the outer surface 38 which affords continuous support co-extensive with the roll shell 12.

FIGURE 9 shows an arrangement for continually driving a roll shell during operation. A roll shell 54 is pro vided with an axially extending annular end extension 57 that is carried in spaced bearings 60. The outer race of the bearings 60 is supported in a self-aligning bearing 61 which accommodates the bending which will occur without stress.

The bearings 60 also support the load on the inner shaft 55 supporting the shoe 56. The shaft 55 is supported at its ends on bearings 62a which are carried in the annular extension 57 which is supported by the bearings 60. The extension is also provided with an end 58 to which a drive sheave is secured.

FIGURE 10 shows schematically a pressure control ar- 'rangement wherein an initial pressure change is made in the force applied to a roll mounted in fixed bearings, and an automatic change is made to the pressure applied to the inner surface of the roll shell. Forces may be applied to the end of an upper roll 60a by air cylinders 68 at the ends of the roll to control roll bending with air being supplied from an adjustable air pressure valve 62. The valve 62 may be manually operated or may be automatically controlled in response to other operational factors of the machine.

The air pressure signal is supplied to a responsive diaphragm 63 which supplies a pressure signal through lines 69 to a diaphragmed pressure balancing chamber 67. The diaphragm of the chamber 67 is connected to a pivotal arm 70 which connects to a diaphragm of a chamber 71. The arm 70 is mounted on an adjustable pivot point and the unit including chamber 67 and 71 is of the type which is available commercially, such as for example, a Hagen ratio totalizer. For convenience of reference, the pressure signals are referred to by the letter I, with the initial air pressure signal I being supplied at the diaphragm 63, and transmitted through the line 69 to register at I and be converted into a signal I The signal 1;; is'supplied to a pressure responsive diaphragm 72 which provides a signal 1,; to control a by-pass valve 73 that regulates the pressure output of an oil pump 74 receiving, oil from a tank 741:.

The output of the pump 74 is supplied through an oil pressure line 76 to a chamber 77 operating on a piston beneath at loading shoe 78 within a roll shell 61a. The shell 61a forms a nip N with the upper roll 60. In the arrangement of FIGURE the loaded roll shell is shown below the mating roll 60a and it will be understood that the roll shell may be either above or below the mating roll and is not limited to a particular position. The pressure supplied through the line 76 is shown as I and a pressure indication signal I is fed from the cylinder 77 to the diaphragm within a pressure chamber 64. The diaphragm acts on a lever arm 65 with its pressure signal I to be converted to a pressure signal I by acting on a diaphragm Within a pressure chamber 66, connected to the lever arm 65. The diaphragm is loaded by a spring 90 but the resistance pressure of the spring 90 can be altered by a modifying signal provided from a valve 79 from a constant air pressure line. By changing the air pressure supply through the valve 79, the relationship between the air pressure and oil pressure can be changed to change the crown of the roll 60a. FIGURE 11 shows three curves M M and M which result from three different settings of the valve 79. The unit including chambers 64 and 66 can also be a Hagen ratio totalizer or equivalent mechanism.

The output signal 1 is supplied to the upper portion of the chamber as signal I The signal I will thus influence the position of the arm 70 and accordingly the pressure transmitted to the channel 77. Changes in the slopes of the pressure relationships M M and M can be varied by changing the location of the pivot point for either the lever arms 65 or 70.

Thus is will be seen that I have provided an improved controlled deflection roll arrangement which meets the objectives and advantages above set forth, and which is capable of obtaining uniform or controlled nip pressure avoiding advantages encountered in devices heretofore available.

The drawings and specifications present a detailed disclosure of the preferred embodiments of the invention, and it is to be understood that the invention is not limited to the specific forms disclosed, but covers all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by the invention.

I claim as my invention:

1. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means,

bearing means between the roll shell and shaft for positioninig the roll shell and to maintain it in alignment with the second roll,

a rigid elongate limber shoe means bendable over its length having an outer surface substantially coextensive with the length of the roll shell and being in axially continuous supporting engagement with the inner surface of the shell opposite the nip with said surface being rigid and of substantially the same radius of curvature as the inner surface of the roll shell and having a leading nose surface spaced from and facing the oncoming roll shell inner surface to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell,

and a controlled fluid pressure loading means mounted on said shaft means applying radially outwardly directed forces to said shoe means along the length thereof so that a continuous nip loading force is maintained within the roll shell independent of bending of the nip with load.

2. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means,

.bearing means between the roll shell and shaft for positioning the roll shell and to maintain it in alignment With the second roll,

a shoe means having an outer surface axially substantially coextensive with the roll shell for continuous supporting engagement therewith and having a radial outer surface of substantially the same radius of curvature as the inner surface of the'roll shell and having a leading nose'surface spaced from and facing the oncoming roll shell inner surface to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell,

means delivering lubricating fluid within the roll shell against the inner surface thereof in advance of said shoe means,

and a controlled fluid pressure loading means mounted on said shaft means applying radially outw ardly directed forces to said shoe means along the length thereof so that a continuous niploading force is maintained within the roll shell independent of bending of the nip with load.

3. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

va non-rotatable shaft means extending through said shell,

means supporting said shaft means,

bearing means between the roll shell and shaft for positioning the roll shell and to maintain it in alignment with the second roll,

a shoe means having an outer surface substantially co-extensive with the length of the roll shell and being in axially continuous supporting engagement with the inner surface of the shell opposite the nip,

said surface being arcuate and convex and of substantially the same radius of curvature as the inner surface of the roll shell and having a leading nose surface spaced from and facing the oncoming roll shell inner surface for building up a supporting film of lubricating fluid between the roll shell and shoe means from fluid within the roll shell,

4. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means,

a shoe means having an outer surface axially substantially co-extensive with the roll shell for continuous supporting engagement therewith and having a rigid radial outer surface of substantially the same radius of curvature as the inner surface of the roll shell and having a leading nose surface spaced from and facing the oncoming roll shell inner surface to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid Within the shell,

a controlled fluid pressure loading means mounted on said shaft means applying radially outwardly directed forces to said shoe means along the length thereof so that a continuous nip loading force is maintained within the roll shell independent of bending of the nip with load,

means defining an axially elongate radially outwardly facing channel on said shaft means,

a fluid pressure line connected to said channel means,

and an elongate piston means supported by the fluid in said channel means supporting said shoe means for applying a radial nip loading force to said roll shell.

5. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means, bearing means between the roll shell and shaft for positioning the roll shell and to maintain it in alignment with the second roll,

a shoe means having an outer surface axially substantially coextensive with the roll shell for continuous supporting engagement therewith and having a rigid radial outer surface of substantially the same radius of curvature as the inner surface of the roll shell and having a leading nose surface spaced from and facing the oncoming roll shell inner surface to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell, a controlled fluid pressure loading means mounted on said shaft means applying radially outwardly directed forces to said shoe means along the length thereof so that a continuous nip loading force is maintained within the roll shell independent of bending of the nip with load,

a fluid pressure line connected to said channel means,

an elongate piston means supported by the fluid in said channel means supporting said shoe means for applying a radial nip loading force to said roll shell,

and a pivotal connection between said piston means and shoe means supporting the shoe means on an axis parallel to the roll shell for accommodating the film of fluid built up between the inner surface of the roll shell and the shoe means.

6. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means,

a fluid pressure line connected to said channel means,

radially facing axially extending recesses in the shoe means and piston means,

and an axially extending pivot pin means in said recesses pivotally supporting the shoe means for accommodating the film of fluid built up between the inner surface of the roll shell and the shoe means.

7. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

21 nLpn-rotatable shaft means extending through said s ell,

means supporting said shaft means,

a shoe means having an outer surface axially substantially co-extensive with the roll shell for continuous supporting engagement therewith and having a radial outer surface rigidly shaped to build up a supporting film of lubricating fluid during relative rotation of the roll s-hell from fluid within the shell,

a fluid pressure line connected to said channel means,

and a radially outwardly facing shoe support surface on said shaft means beside said channel means,

said shoe means being circumferentially wider than the channel and resting on said surface with the collapse of pressure in said channel means.

8. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

a shoe means having an outersurface axially substantially co-extensive with the roll shell for continuous supporting engagement therewith and having a rigid radial outer-surface of substantially the same radius of curvature as the inner surface of the roll shell and having a leading nose surface spaced from and facing the oncoming roll shell inner surface to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell,

a controlled fluid pressure loading means mounted on said shaft means applying radially outwardly directed forces to said shoe meansalong the length thereof so that a continuous nip loading force is maintained within the roll shell independent of bending of the nip with load,

a fluid pressure line connected to said channel means,

and a plurality of pistons located in said channel means each supported by the fluid in said channel means and each supporting said shoe means for applying a radial nip loading force to said roll shell.

.9. A roll assembly for forming a pressure nip with a second roll comprising;

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shalft means,

a shoe means having an outer surface axially substantially co-extensive with the roll shell for continuous supporting engagement therewith and-having a rigid radial outer sunface of substantially the same radius of curvature as the inner surface of the roll shell and having a leading nose surface spaced from and facing the oncoming roll shell inner surface to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell,

a plurality of 'pistons located in said channel means each supported by the fluid in said channel means and each supporting said shoe means for applying a radial nip loading force to said roll shell,

rigid dividers in said channel means between said pistons separating the channel means into a plurality of individual chambers,

and fluid pressure lines connected to the chambers.

10. A roll assembly vfor forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means,

bearing means between the roll and shaft for positioning the roll shell and to maintain it in alignment with the second roll,

a shoe means having an outer surface axially substantially co-extensive with the roll shell for continuous supporting engagement therewith and having a radial outer surface rigidly shaped to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell,

and fluid scoops on the shaft means for removing excess fluid from the inner surface of the roll shell.

11. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means,

a shoe means having an outer surface axially substantially co-extensive with the roll shell for continuous supporting engagement therewith and having a ta 7 dial outer surface rigidly shaped to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell,

a controlled fluid pressure loading means mounted on said shaft means applying raldially outwardly directed forces to said shoe means along the length thereof so that a continuous nip loading force is maintained within the roll shell independent of bending of the nip with load,

and a fluid return passage means having an inlet immediately at the ends of said shoe means receiving excess fluid which does not form a film between the shoe means and roll shell.

12. A roll assembly for forming a pressure nip with a second roll comprising:

an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

means supporting said shaft means,

end bearings between the ends of the roll shell and shaft means,

fluid end scoops on the shaft means projecting for moving fluid from the inner surface of the roll shell,

passages leading from the scoops to said end bearings for lubricating the bearings from the scoops,

and means pivo-tally supporting said shoe means about an axis parallel to the roll axis for pivotal movement relative to the inner surface of the roll to conform to the pressure of the fluid film between the shoe means and roll shell.

13. A roll assembly for forming a pressure nip with a second roll comprising:

65 an outer tubular cylindrical roll shell,

a non-rotatable shaft means extending through said shell,

self-aligning bearings supporting each end of the shaft means,

and means pivotally supporting said shoe means about an axis parallel to the roll axis for pivotal movement relative to the inner surface of the roll to conform to the pressure of the fluid film between the shoe means and roll shell.

14. A roll assembly for forming a pressure nip with a second roll comprising:

a shoe means having an outer surface axially substantially co-extensive with the roll shell for continuous supporting engagement therewtih and having a rigid radial outer surface of substantially the same radius of curvature as the inner surface of the roll shell and having a leading nose surface spaced from and facing the oncoming roll shell inner surface to build up a supporting film of lubricating fluid during relative rotation of the roll shell from fluid within the shell,

means defining an axially elongate radially outwardly facing continuous channel extending the full length of each shaft means and opening from the ends thereof,

plate means on the ends of said channel means,

a fluid pressure line connected to the channel means,

and an elongate piston means supported by the fluid in said channel means located between said plate means and supporting the shoe means for applying a radial nip loading force to said roll shell.

References Cited by the Examiner UNITED STATES PATENTS 242,058 5/ 1881 Schurmann 291 16 1,868,860 7/1932 Von Reis. 2,395,915 3/1946 Specht 29116 X 2,854,700 11/1958 Caspari et al. 1965 2,960,749 11/ 1960 Robertson et al 291 16 X 3,106,153 10/1963 Westbrook 155 3,119,324 l/1964 Justus 100170 3,131,625 5/1964 Kusters et al. 100170 LOUIS O. MAASSEL, Primary Examiner.

WALTER A. SCHEEL, Examiner.

Claims

1. A ROLL ASSEMBLY FOR FORMING A PRESSURE NIP WITH A SECOND ROLL COMPRISING: AN OUTER TUBULAR CYLINDRICAL ROLL SHELL, A NON-ROTATABLE SHAFT MEANS EXTENDING THROUGH SAID SHELL, MEANS SUPPORTING SAID SHAFT MEANS, BEARING MEANS BETWEEN THE ROLL SHELL AND SHAFT FOR POSITIONING THE ROLL SHELL AND TO MAINTAIN IT IN ALIGNMENT WITH THE SECOND ROLL, A RIGID ELONGATE LIMBER SHOE MEANS BENDABLE OVER ITS LENGTH HAVING AN OUTER SURFACE SUBSTANTIALLY COEXTENSIVE WITH THE LENGTH OF THE ROLL SHELL AND BEING IN AXIALLY CONTINUOUS SUPPORTING ENGAGEMENT WITH THE INNER SURFACE OF THE SHELL OPPOSITE THE NIP WITH SAID SURFACE BEING RIGID AND OF SUBSTANTIALLY THE SAME RADIUS OF CURVATURE AS THE INNER SURFACE OF THE ROLL SHELL AND HAVING A LEADING NOSE SURFACE SPACED FROM AND FACING THE ONCOMING ROLL SHELL INNER SURFACE TO BUILD UP A SUPPORTING FILM OF LUBRICATING FLUID DURING RELATIVE ROTATION OF THE ROLL SHELL FROM FLUID WITHIN THE SHELL, AND A CONTROLLED FLUID PRESSURE LOADING MEANS MOUNTED ON SAID SHAFT MEANS APPLYING RADIALLY OUTWARDLY DIRECTED FORCES TO SAID SHOE MEANS ALONG THE LENGTH THEREOF SO THAT A CONTINUOUS NIP LEADING LOADING FORCE IS MAINTAINED WITHIN THE ROLL SHELL INDEPENDENT OF BENDING OF THE NIP WITH LOAD.