US3001580A - Wire drive roll mounting and method - Google Patents

Description

Sept; 26, 1961 E. D. BEACHLER ,00

was DRIVE ROLL MOUNTING AND METHOD Filed May 19, 1958 2 Sheets-Sheet 1 P2102 HET O 0 L] L] U L1 L1 L] L] /3 3 i l6 F 3 ,2 13 2b 1) b ou b t a I i [Hz/En [Ur fda/dra 0. Beach/er Qi gg (4 P .W W? 5 5 17/457 5.

Sept. 26, 1961 E. D. BEACHLER 3,001,580

WIRE DRIVE ROLL MOUNTING AND METHOD Filed May 19, 1958 2 Sheets-Sheet 2 1 l 3/ I 5' l f L II' [Hz E2710? Edward .0. fieac/z/er United States Patent 3 39, V WIRE-DRIVE ROLL MOUNTING AND. METHOD Edward D. Beachler, Beloit,.Wis., assignor to Beloit Iron Works, Beloit, Wis., a corporation of Wisconsin Filed May 19, 1958, Ser. No. 736,371 4'Claims. (Cl. 162-348) The instant invention relates to a mounting for a roll for driving a looped traveling band, and more particularly, to a wire drive roll mounting for driving a forming wire, such as the forming Wire of a Fourdrinier type paper making machine.

Although the instant invention may have application in a number of fields, it is uniquely adapted to the operation of paper machines, and particularly the driving of forming wires in paper machines, and the invention will be described in detail with respect to. this particular aspect. In the operation of the forming wire "heretofore in paper machines, the forming wire is mounted with an upper run extending from a breast roll at the rear end to a suction couch roll at the forward end, of the top reach of the wire, with suction boxes beneath the top reach and adjacent the couch roll, and the bottom reach or return reach of the looped wire is supported on a number of return rolls. Although it was earlier the accepted practice to drive the forming wire through, the suction couch roll, recently the advantages of using the return rolls as drive rolls have been discovered. In particular, it has been found advantageous to drive the wire with drive rolls mounted outside the loop of the Wire and engaging the outer surface of the wire. In the case of such rolls the wire passes over the top of'the drive rolls.

These various changes in wire drive arrangement have resulted in a much longer wire life. As will be, appreciated, the changing of a worn out wire involves a, production shutdown of an appreciable period, of time plus the cost of a new Wire (which itself may be as much as $4,000.00). The production loss is the greatest financial loss here involved. The instant invention relates to still another improvement in wire drive mechanism which gives still longer life to the wire and avoids certain particular types of damage to the wire. One type ofdamage to the wire which the instant invention tends to avoid is known as ridging and this involves the folding of a portion of the wire onto itself at one place or another in its travel.

In accordance with the instant invention, back-up, means as provided for engaging the central portion of the drive roll to correct the natural tendency for the roll to de' fiect, and even to induce deflection of the roll in the-opposite direction. By the use of the instant back-up means, it is possible to obtain greater wire life and, to avoid any tendency toward ridging in the operation of the wire.

It is, therefore, an important object of the instant invention to provide an improved Wire drive roll mounting.

It is another object of the instant inventionto provide an improved papermachine arrangement comprising -a looped forming wire, a roll engaging the wire and having normally a central deflection, and a back-up means engaging the central portionof said roll to relieve the normal deflection thereof.

Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed disclosure thereof and the drawings attached hereto and made apart hereof.

On the drawings:

FIGURE 1 is an essentially diagrammatic side elevational view of a paper machine of the Fourdrinier type;

FIGURE 2 is a diagrammatic view showing forces applied to a drive roll in the paper machine of FIGURE '1;

ice

3 is an exaggerated essentially diagrammatic top plan view of a drive'roll mounting ofthe prior art;

FIGURE 4 is an essentially diagrammatic side elevational view of the device of FIGURE 3;

FIGURE 5 is a diagrammatic topplan View drawn along the lines of FIGURE 3, but showing an embodiment of. the instant invention;

FIGURE 6 is a diagrammatic side elevational view of the device of FIGURE 5 FIGURE 7 is a top plan view drawn along the lines of FIGURES 3 and 5,. but showing another embodiment of the instant invention; and,

FIGURE 8 is, adiagrammatic'side elevational view of the device of FIGURE 7.

As shown on the drawings:

In FIGURE l-there is shown a paper machine indicated generally by the reference numeral 10, which comprises a, head box 11 for flowing stock onto the top run 12a of a looped forming wire 12. The top run 12a of the wire 12 extends from a breast roll 13 over table rolls 14 and suction boxes 15 to a couch roll 16, The Wire. 12 then passes around. a turning roll 17 and over and under return, end guide rolls 18, 19, 20 and 21 back to the breast roll 13. In the paper machine 10, one of the rolls which will drive the wire, 12 is the drive roll 20 mounted outside the loop of the wire 12.

In. FIGURE 2, a diagram ofsome of the forces applied to the roll 20 is shown. The wire 12 (traveling in the direction indicatedby. the arrow) passes over the top of the roll 20 and wraps the roll 20 by a total angle of wrap of 2 alpha. As here shown the oncoming side 12b of the wire 12, strapsthe roll 20 over the. angle alpha and the oif-running side 12c of the wire also wraps the roll over the angle alpha with the dividing line v therebetween being a substantially vertical line passing through, the center of the roll 20. The tension on the wire 12 thus applies a force in an essentially downward vertical direction indicated by the arrow A.

The weight of the roll 20 also applies a force in, the direction ofthe arrow A. It will be appreciated, that loading forces such as the 'weightof the roll and the tension on the wire 12 load the roll 20 as a beam. And the roll 20 has a substantial length compared to its diameter. For example, in a typical paper machine the roll 20 will be approximately 20 feet long and only approximately 1V2 feet in diameter.

It will further be appreciated that, when the roll 20- is rotated in 'the'directionindicated by the arrow (on the roll 20-) there is a load applied across the top of -the roll in a direction generally tangential to the roll portion wrapped by the wire12. The wire 12 resists being driven to this extent so as to apply this, load to the roll 20 and this load applies generally in the direction of the line of force B. The resulting sum of all of the loads applied to the roll 20 may be, indicated by the force line C and this generally is the directionin which the roll 20 tends to deflect in the'central portion thereof. It will be noted that the roll tends to deflect in a direction downwardly and toward the oncoming wire (12b).

Referring now to FIGURES 3 and 4, it will beseen that the deflection is shown in exaggerated form. In FIGURE 3' the roll 20 is shown with one journal 22 rotatably mounted in drive means 23 (indicated diagrammatically) and the other journal 24 rotatably mounted in bearingmeans 25. The wire 12 passes 'over the top of the roll 20; and it will be seen that the roll 20 is deflected in its. central portion 20a backwardly or in the direction of the oncoming side 12b of the wire 12. As shown in FIG- URE 4, the central portion 20a of the roll 20 is deflected ofl-center from the drive means 23 and the extreme edge of the roll, which is a full line marked 20. The central portion 20a is deflected toward the oncoming side 12b of the wire and also downwardly. This results in a dragging of the central portion of the wire 12 as it passes over the roll 20 and also is believed to result in the application to the wire of transverse forces in the directions indicated by the arrows E of FIGURE 3. Thus, although the. oncoming side 12b of the wire 12 may have no transverse forces applied thereto and the wire 12 may be traveling in substantially a straight line in a plane generally tangential to the roll 20 (as indicated by the arrows b), once the wire 12 passes over the bowed or deflected roll 20, there is a tendency for the edges of the wire at the off-running side 120 to be urged inwardly (as indicated by the arrows Although it is not desired to limit the invention to any particular theory, the theory which is now being explained does appear to give a logical explanation for the results obtained in the prior art and in the practice of the instant invention. This I transverse compression of the off-running wire side 12c tends to offer an opportunity for the wire to ridge, particularly if any slight forces may be applied normal to the plane of the wire (for example, by fibers or some dirt or impurity adhering to the roll and passing between the roll 20 and the wire 12).

In FIGURES 5 and 6, there is shown one embodiment of the instant invention which is a drive roll arrangement indicated generally by the reference numeral 30. In the arrangement 30 a drive roll 31 is driven by suitable drive means 32 (shown diagrammatically) rotatably mounting a journal 33 of the roll 31. Bearing means 34 rotatably mount the other journal 35 of the roll 31. A wire 36 passes over the roll 31 and is driven thereby in the direction indicated by the arrows in FIGURE 6. The roll 31 would normally have a central deflection, that is, the Weight load, tension load and load imposed by driving of the wire 36 tend to deflect the roll 31 in the central portion 31a thereof. However, back-up means in the form of a back-up roll 37 engage the central portion 31a of p the roll 31 to relieve the normal deflection thereof. As

7 shown, the back-up roll 37 engages the underside of the drive roll 31 to counteract its tendency to deflect. As will be appreciated, a plurality of back-up rolls 37 may be used, but a single roll is ordinarily adequate. The back-up roll 37 is mounted on adjustable means (indicated diagrammatically at 38), so that compensation may be made for different tension loads and different driving speeds which may alter the load applied to the roll 31 by driving at the down-running side of the roll 31 to keep the roll clean and avoid having fibers and the like particles passing through the nip defined by the rolls 31 and 37. The doctor 39 may also apply a load to the roll 31 and the back-up roll 37 is mounted to compensate also for this change in the overall load. In general, the centers of the rolls 31 and 37 are aligned generally in the line of the sum of all the forces applied to the roll 31. This force line was indicated as the line C in FIGURE 2. The roll 37 is thus ordinarily mounted beneath the roll 31 to compensate for the heavy weight load and also toward the oncoming side 36a of the wire 36 to compensate for the driving load.

As indicated in FIGURE 5, the oncoming side of the wire 36 does not have any transversely aligned forces applied thereto, and by maintaining the roll 31 in a substantially undeflected alignment (as shown in FIGURE 5) the ofl-running side 36b of the wire 36 also has no transverse forces applied thereto and the wire leaves the top of the roll 31 in a generally tangentially aligned plane as indicated by the arrows a.

Although the alignment of FIGURE 5 is theoretically ideal and the back-up means 37 should be applied so as to just compensate exactly for the tendency to deflect the roll 31, there may be difficulties with changes in tension during operation of the wire 36 and/or other operating changes. For this reason, the embodiment shown. in' FIGURES 7 and 8 is to be preferred.

In FIGURES 7 and 8 there is shown a roll 40 with one journal 41 rotatably received by drive means 42 and the other journal 43 rotatably received by bearings 44. A wire 45 passes over the top of the roll 40 having an oncoming side 45a and an elf-running side 4517. Back-up means in the form of a back-up roll 46 is provided to engage the underside of the drive roll 46 and actually deflect the central portion 40a of the roll 40 in the direction opposite to the direction in which the roll 40 would normally tend to deflect. In other words, the back-up means 46 deflects the central portion 40a of the roll 40 upwardly and toward the off-running wire 451). A doctor 47 is provided for the down-running side of the roll 4% 7 The advantage of the mounting for the roll 40 is that this roll is so deflected in the central portion 40a that it applies outwardly directed transverse forces to the olfrunning wire 45b. along the lines indicated by the arrows e. At the oncoming side the Wire 45a is in substantially straight line alignment was indicated by the arrows 7, but when it passes over the roll .40 it is actually spread trans versely ever so slightly. This slight application of outwardly directed transverse force not only makes certain that'a change of operating conditions will not result in the application of inwardly directed transverse forces, but also makes certain that particles of dirt, fibers, and the like which may pass between the roll 40 and the wire will not ordinarily impart forces normal to the plane of the wire of suflicient magnitude to cause ridging or other damage to the wire. In other words, it has been found that it is actually advantageous to apply a slightly distorting force to the wire 45 as it passesoverthe drive roll 40, as'long as such forces are outwardly directed transversely to the wire travel. I

In order to fully understand the instant invention it must. be-appreciated that the deflections here shown are greatly exaggerated. Actually, in the operation of the 7. paper. machine the deflections are not visible to the naked eye. For example, in operating the embodiment of FIGURES 7- and 8, the roll 49 is deflected upwardly approximately 0.022 inch at the middle 40a thereof, in the case of a roll about 20 feet long and 1 /2 feet'in diameter. This is approximately a deflection of 0.01

' 'inch per foot of length. This apparently insignificant the wire 36. Also, a doctor 39 (FIGURE 6) is provided ,7

amount of deflection, however, brings about a unique result in the practice of the invention. The massive size of paper machine equipment, the very substantial forces applied and the high speeds employed make possible the substantial improvement. over the prior art that is obtained by either correcting the downward deflection or actually slightly reversing this deflection.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of the present invention.

I claim as my invention} 1. In a paper machine, a drive'roll, a forming wire passing over the top of the roll, drive means rotating said drive roll to drive the wire thereover, the weight load on the drive roll and the driving thereof against said Wire tending to deflect the roll in a direction downwardly and toward the oncoming wire, and a back-up roll engaging the underside of said drive roll to counteract its tendency to deflect.

2. In a paper machine, a drive roll, a forming wire passing over the top of the roll, drive means rotating said drive roll to drive the Wire thereover, the weight load on the drive roll and the driving thereof against said wire tending to deflect the roll in a direction downwardly and toward the oncoming wire, and a back-up roll engaging the underside of said drive roll. to deflect the drive roll upwardly and toward the off-running wire.

3. In a paper machine, a drive roll, a forming wire passing over the top of .the roll, drive means rotating toward the oncoming wire, and a back-up roll engaging the underside of said drive roll to counteract its tendency to deflect, said back-up roll being of substantially less width than that of the drive roll and engaging a portion of the drive roll intermediate the ends thereof.

4. In a paper machine, a drive roll, a forming Wire passing over the top of the roll, drive means rotating said drive roll to drive the wire thereover, the weight load on the drive roll and the driving thereof against said Wire tending to deflect the roll in a direction downwardly and toward the oncoming wire, and a back-up roll engaging the underside of said drive roll to deflect the drive roll upwardly and toward the off-running wire, said back-up 6 roll being of substantially less width than that of the drive roll and engaging the central portion of the underside of said drive roll.

References Cited in the file of this patent UNITED STATES PATENTS Re. 16,218 Darby Dec. 1, 1925 1,885,334 Darrah Nov. 1, 1932 2,484,473 Staege Oct. 11, 1947 2,780,967 Dearden Feb. 12, 1957 2,782,693 Williams Feb. 26, 1957 2,798,414 Muggleton July 9, 1957

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