US2797635A - Cane crushing mill - Google Patents

Description

July 2,` 1957 n E. w. KPKE 2,797,635

, CANE: cRusI-IING MILL.

Filed July 22. 1953 3 Sheets-Sheet l INI/'E N TOR.

H/:NTORNE xr, Y

July 2, 1957 E. w. KQPKE 2,797,635

. CANE CRUSHING MILL Filed July 22. -19525 3 Sheets-Sheet 2 MMJM July 2, 1957 Filed July 22. 1953 E. W. KPKE VCANE CRUSHING MILL 3 Shets-Sheet 5 INI/ENTok.

United States arent fce CANE CRUSHING MILL Ernst W. Kopke, New York, N. Y.

Application July 22, 1953, Serial No. 369,547

Claims. (Cl. 10U- 165) This invention relates to crushing mills, more particularly to three-roll mills for crushing sugar cane and like materials.

In many conventional mills as heretofore made, pressure was applied by the feed roll against .a floating top roll, the function of the said rolls being to compact the mat of fibrous material as much as practical and in doing so `to extract as much juice as possible. In those mills adjustment of roll settlings .and the amount of pressure applied between the top and feed rolls was such as to tend to bring about the above-.mentioned objectives to such a degree as would not restrict their capacity requirements. Since sliding movement of the top roll was in a single plane, it was obviously impossible for such single plane movement to compensate for wide variations of material density and quality which occurred independently and separately at the feed and discharge pressure lines.

The two major functions of a crushing mill are to cope with widely varying conditions of feed and to maintain a high degree of juice extraction. Although in conventional mills a somewhat lower pressure exists 'between the feed and top rolls than between the discharge and top rolls, those conditions are subject to wide pressure variations which seriously interfere with the results both in the capacity of the mill unit and in the amount of juice which it extracts. The wide variationsin results are due largely to the fact that the density, volume and quality of the material under pressure between the feed and top rolls is very rarely the same as that which at the same time is being kpressed between the top and discharge rolls.

The conventional type mills of the three-roll type have been functionally deficient because they lack means for `maintaining uniform pressure between the top and feed rolls and between the top and discharge rolls. A single top pressured roll with its movement restricted to a single plane cannot maintain constant pressure on two pressure lines in which the density, volume and quality of material is varying widely and continually. 'The truth of this is abundantly evidenced byiindividual mill extraction tests which when repeated many times at short intervals and with the same setting and same hydrostatic pressure on the rolls and the same operating rate and quality of cane show wide differences in the amount of juice extracted.

Efforts to compensate for these functional irregularities have caused sugar producers to install additional mill units. However, the theoretical benefit of such additional facilities isf largely `nulliiied in actual operations for several reasons., one of the .most important being the ,problem o'f maintaining the required operating rate.

`of the multiplicity of milling .units lies mainly in the .number of macerations. Since water is applied .between the last `two mill units and the relatively dilute juice extracted bythe last mill is returned Vand applied to the material before it enters the next to the last mill, the dilute juice can be returned once in a mill tandem comprising three milling units. In 'the case of a four-mill tandem it can be done twice. It is significant, however, that extractions obtained by the great majority -of multiple milling installations are no better than and often inferior to the extractions obtained by tandems of fewer units.

In an effort to improve individual mill performance, and at the same time to provide a mill structure which will allow use of roller bearings, I propose to use a top and pressured roll and a pressured discharge roll each of which has individual 'means applying pressure to the bearingsof those rolls.

In using roller bearings itis essential that pinching forces of the journals in the bearings and of the pressure means on the bearing boxes be avoided, in order `not to shorten the life of the bearings and journals. It is necessary therefore to devise new bearing mountings which will permit the unavoidable misalignment of roller axis with respect to one another but which will at the same time avoid subjecting the bearings to said 4pinching forces.

Therefore, it is an object of lthis invention to provide uniform adjustable pressuring of the top roll against the feed `roll and the material passing between the two and to concomitantly provide `separately .uniform adjustable pressuring of the discharge roll against the top roll and the-material passing between them.

Another object of the invention is to provide for movement of the top roll to or from the feed roll in conformity with the varying density and thickness of the material being pressed -by novel means which permit freedom of misalignment of the `top roll relative to the feed roll without imposing pinching pressure on roller bearings.

Another object of theinvention is to provide for movement of the discharge roll ,to or from the top roll in conformity with varying density or thickness of material being `pressed .by novel .means which permit freedom of misalignment `of the discharge roll relative to the top roll.

Another object of the invention is to provide for relative misalignment of the discharge roll relative to the top rolland at the same time to provide for and permit rleative .misalignment of the top roll `relative tothe feed roll, both without imposing pinching pressure -on the ,bearings of any of the said rolls.

Another object of the invention is to provide for use Vcaf-enclosed roller bearings of the type which takes into account both thrust and radial loads by providing a .novel mounting for such bearings.

.Another object of the invention is to provide a novel mounting for heavy duty roller bearings which permits fclosing in of the rolls by reducing the thick-ness of the stop blocks so as to maintain proper distances between the roll surfaces while shortening center distances so as totake up roll surface wear.

4Other objects and advantages of the invention will ap- .pear as it is described in connection with the accompanying drawings.

In .the drawings, Figure 1 is a side elevation view 4partly in section of a three-roll mill embodying the invention.

Figure 2 is a vertical section vlew taken along line 2 -2 of Figure l.

:Figure 3 zis -a vertical section view taken along line 3-3 of .Figure 1.

.Figure A lis a fragmentary perspective view of the top roll ybearing chock and mounting parts associated therewith.

Figure is a fragmentary perspective view of the discharge roll bearingchock and associated mounting parts.

Referring to the drawing, the feel roll FR, top pressure roll TR and discharge roll DR have their journals mounted in bearings in similar right-side and left-side supporting frames or housings. The right and left-side housings may each comprise a main supporting member consisting of a vertical plate having a horizontal bottom flange resting upon a bedplate 13 and an upper horizontal flange 12 on which is supported a feed roll bearing-box 14. The feed roll bearing-box may have a liner 14b. At one side of the main supporting member 10 as viewed in Figure lis mounted a cap plate 15 through which is threaded a jack screw 16 for'moving the feed roll bearing box 14 in a horizontally inward direction. For moving the feed roll' bearing box horizontally outward a withdrawing screw `17 is attached to the bearing box and passes through the cap plate and has a nut mounted upon its outer end. The main supporting member is also provided with a turn beam supporting bracket 18 on which is mounted a `turn beam bearing box 19.

The top roll mounting Supported upon the main supporting member 10 in inclined position on the opposite side of the feed roll axis from the cap plate 15 is a front frame plate 20. Secured to the front plate 20 at its top is a cap plate 22, by bolts 23 passing through a flange 22 of the top cap plate lying against the front frame plate. A key 24 between the flange 22 and front plate 20 holds the top cap plate from movement relative to the front plate.

Also secured to the front frame plate 20 in a position spaced from and below the top cap plate 22 is a guideway and supporting plate 26 extending perpendicular to the main frame plate and secured thereto by bolts extending through a flange 26 which lies flat against the surface of the main frame plate. In the central portion of said guideway and supporting plate is a rectangular guideway or opening 27 (see Fig. 4) in which is fitted a sliding rectangular block 28 in the center of which is formed a circular` bearing recess, the purpose and function of which will be more fully described hereinafter.

Between the top cap plate 22 and the guideway and supporting plate 26 is slideably mounted a top roll bearing box 30 .in which a journal of the top roll is mounted.

Due to the irregular feed of cane to the feed and top rolls, the top rolltends to tilt so that its axis is not parallel at all times to the feed roll axis. Indeed this nonparallelism Vor misalignment is the ,rule rather than the exception in many cases.

To permit this tilting the bearing blocks of the top roll are slideably mounted to move in a plane which is oset from and slightly above the axis of the feed roll. This location of the plane of the top roll bearing movement is due to the desireto have the plane or line of action of the top roll bearings at right angles to a plane through the top roll and discharge roll axes.

As the top roll tilts, one or both ends tend to move different distances. Any pinching of the roll journal in its bearing causes excessive wear of the bearings. Sliding alone of the bearing blocks is not enough to maintain the bearing axes in alignment with the journal axis; therefore, I have provided means for the bearing blocks to pivot as well as to slide within their guideways.

To facilitate the sliding movement there is provided between the top surfaces of the bearing block and the adjacent surface of the top cap plate 22 a ladder-type 'roller bearing comprising parallel hard surface wear plates 32a, 32]; between which are bearing rollers 32 conventionally held within a retainer 33. The provision of this roller bearing is necessary when taking'into account and providing for the thrust of the discharge roll against the top roll, the whole force of which is transmitted to the top cap plate through said roller bearing.

The bottom side of the top roll bearing box 30 is provided with a cylindrical bearing boss 31 or stud which tits in the circular hole 29 in the rectangular bearing block Z8 that slides in the guideway 27 of the plate 26. Thus the top roll bearing box 30 is slideably supported at the top by the roller bearings 32 and at the bottom by the block 28. The bearing box can pivot about the boss 31 while sliding with the guide block 28 so that the axis of the bearing box 30 is maintained in alignment with the axis of the top roll journal at all times. Also the vertical axis of the boss 31 always passes through the center of the axis of the journal and its bearing due to the fact that the bearing is locked against axial movement relative to the journal by locking ring r on one side and, on the other side, is solid against a shoulder s of the roll shaft.

Pressure is applied to the top roll by an hydraulic ram to which a liquid is fed under pressure through a pipe 35 from an accumulator (not shown). There is a separate accumulator for each ram and a ram for each of the top roll bearing boxes.

The hydraulic cylinder may be conveniently supported from a back frame plate 40 parallel to and spaced from the front frame plate 20 and extending from the top cap plate 22 downwardly. A flange 40 formed on the back frame plate is bolted to the top cap plate 22. An end thrust key 43 between ange 40 and top plate 22 prevents relative movement therebetween.

Each ram comprises a cylinder 34 in which slides a piston 36, the bottom end of which projects from the end of the cylinder. Between the end of the piston and a flat pressure plate 38 located on that side of the top roll bearing block which faces the piston a connection is provided which will prevent pinching and restriction of the movement of the hydraulic ram piston when tilting of the top roll occurs. Such connection comprises a small cylindrical aligner roller 41 mounted in a retaining cage 42 and positioned so its axis is perpendicu lar to the plane in which the top roll moves. The cage 42 may be cast or machined from a block of metal with an inner chamber opening toward the press plate 38 and containing said roller 41. An outer chamber may also be provided in the cage opening to the inner end of the piston 36 and containing a second cylindrical aligner roller 44 against which the end of the piston presses. The second aligner roller is so located that its axis is perpendicular to and offset from the axis of the first aligner roller, i. e., in the plane in which the top roll axis moves. It may thus be seen that as the bearing block 30 at one end of the top roll moves against the force of the piston, the rst aligner roll 41 will facilitate movement of the bearing box relative to the piston end. The other aligner roll 44 permits the bearing box to move slightly in a direction parallel to the front frame plate 20, as may be necessary due to wear of the supporting plate 26 or the top cap plate 22 or due to slight clearance between them and the bearing box 30. The provision of this second aligner roll 44 is necessary because even a very slight movement of this sort can cause extreme pinching and loss of proper functioning of the top roll hydraulic ram;

From the foregoing 'it will be understood that although the bearing box 30 can move as a whole slideably between the roller bearings 32 and thev guide plate 26, the bearing box canalso pivot about the axis of the boss 3.1 which passes through the center of the bearing'. The bearing and journal are thus always kept in line and pinching is avoided when the roll axis tilts.

roll bearing-boxes 50 which slide between the front and back frame plates. There is a like need for enabling the bearings of the discharge roll to pivotand slide .toavoid pinching and excessive wear of the bearings by the journals as in the top roll.

Sliding movement of the discharge roll bearing boxes is provided by channel or U-shaped slipper plates 51, 52 which slide along the front and back frame plates 20, 4t) on bearing surfaces provided on the inwardly directed faces of the frame plate. The parallel side portions Sla, 51b of the slipper plate extend thereon along side surfaces on the front and back frame plates and thus prevent lateral movement of the slipper plates relative to the frame plates while at the "same time guiding their longitudinal movement. In the central portion of each slipper plate 51, 52 there is provided a circular bore or aperture 53 to receive cylindrical coaxial bearing bosses or trunions 54, 54 mounted upon opposite sides of each discharge roll bearing-box and extending therefrom.

To limit the movement of the discharge roll bearing boxes pairs of stop blocks'SS-SS may be provided above and below the slipper plates and bearing boxes adjacent the front and back frame plates 20, 40 so that when in the upper extreme position the slipper plate and bearing box will abut the upper set 57, 58 of stop blocks while in the lower extreme position of movement the other sides of the slipper plates and bearing will engage the lower set 5S-56 of stop blocks.

It will thus be seen that the slipper plates and ,trunnion mountings or bosses 54 on the discharge roll bearingboxes enable the discharge roll bearings to.slide longitudinally up and down the frame when the discharge roll axis tilts. At the same time each bearing box lcan pivot about its trunnion axis to maintain the bearing axis in alignment with the axis of the discharge roll.

Pressure is applied to each discharge roll bearing box by means of an hydraulic `ram comprising a cylinder 64 secured between the lower ends of the front and back frame plates 20, 46 by bolts or inothersuitable and Vconventional fashion. A piston 66 works Within the cylinder and has its end extending from the cylinder'into engagement with a cylindrical roller 68 whose .axis is perpendicular to the plane in which the discharge roll moves. The roller 68 is mounted in a cage or.retair1er 70 secured to the bottom side of the Vdischarge roll bearing box.

Eaclrram actingiupon the discharge roll bearing boxes derives its pressure from a separate accumulator (not shown) through a pipe 72 so that pressure may be individuaily maintained on each bearing .box of predetermined amount without any limitation being' imposed thereon by the pressure being applied to the ram acting on the other bearing.

By reason of the means above described for mounting the bearings of the top and discharge rolls so that they will always remain iin alignment with the axis of the particular roll supported thereby, it is possible to use roller bearings for the top kand discharge roll journals which use has heretofore not been feasible in cane crushing mills.

Heretofore mill `engineers have been unwilling to use roll necks yor journals of less than standard diameters. This has meant that such types of roller bearings as have been available would have required such large outside diameters as to leave insufficient space to take up for roll wear. Hence, roller bearings either could not be used or if used, they would have required purchase of new shells for the mill rolls about three times as often as would have been the case if normal clearance was available for taking up the roll wear. Since the roll shells are extremely expensive, it was thus impractical to use roller bearings. In recent years roller bearings have been manufactured which provide for considerably smaller outside diameters in ratio to the inside diameter or bore than in previous designs. In developing the present invention the benet of this modern roller bearing G `designihas beenavailed of, with the result that it becomes -poss'ible to use "the standard 4diameter roll neck While still leaving ample `clearance for roll wear takeup.

Although the roller bearing structures individually form no part of my invention they may be described generally as four-row tapered type roller bearings.

Another' disadvantage inpprevious attempts to use roller bearings for the rolls of can mills layin the inability'to properly `allow Vfor swivelling of the bearing blocks. In ordinary practice, allowance for swivelling wasusually made by simply setting the hydraulic plunger or piston against a knife-edge or slight crown, thereby allowing for a certain amount of misalignment or rocking, but such rocking would throw the rollsout of contact position and cause `damaging pressures against the roll circumferential grooving and against the top roll flange. Such pressure was sutiicient at times to break off the hange. In the'case of the present invention the swivelling `movement centers at the middle of the journal instead of on a knife-edge or crown.

ln Figure 2 there is shown in dotted lines H & F `the center of pivotingrnovement of the ydischarge roll :bearing sboxes, which is the axis of the trunions of the bearing boxes, In that figure is also indicated the 'point K at which the pivoting would take place in 'old lstyle bearings mountings which would cause movement at the `top too great to be permissible in connection with the use of roller bearings.

Although the bearing structure .and mounting as described for the top roll and for the discharge roll can be applied to the journals at both ends of the respective rolls, it maybe unnecessary or undesirable in some instances to apply it at both ends- In 'sugar cane mills Vhot water or juices are often applied to the-cane between two-mills, with the result that the rolls become hot and expand. If, as is often the case, the bearing is fixed or locked to the journal so that any movement longitudinally due to heat and'expansion of the end of the shaft carries the bearing along, it is necessary to leave sufcient room or play in order to permit suchexpansion Without pinching or binding.

if the bearing at one end is allowed to float longitudinally with such Vlongitudinal expansion, pinching and binding will be avoided. Hence in some instances the `novel form of bearing mounting herein described will be used only onione end, usually the gear or drive end ofthe rolls.

Because of the unrestricted response of the top and .discharge rolls to variation in density volume and quality of the material, the capacity of the mill unit is substantially increased over conventional mills. Also greater and more uniform pressure can be applied while the life of the parts is increased and more juice is extracted.

Many modications within the scope of my invention will become apparent to those skilled in the art. Therefore I do not limit the invention to the specific improvement illustrated and described herein.

l claim:

l. In a crushing mill, a feed roll, a discharge roll, and a top roll cooperating with said feed anddischarge rolls, bearing means for certain of said rolls, means to mount said bearing means to permit tilting movement of its `roll toward and from another roll, a hydraulic ram to apply hydraulic pressure to the tilting roll to press it toward said other roll, and means to support said bearing means for pivotal movement about an axis perpendicular to the plane of tilting, said pivotal supporting means for the bearing means being spaced from the axis of said hydraulic ram.

2. A crushing mill as claimed in claim l wherein the bearing mounting comprises a sliding block, a pivot boss -on the bearing engaging in an aperture in said block providing for pivotal movement of the bearing relative to said block as the latter slides.

3. A crushing mill as claimed in claim l wherein one bearing mounting of the top roll includes a slidably mounted block, said block having an aperture therethrough, a pivot boss on the bearing engaging in the aperture in said block providing for pivotal movement of the bearing relative to said block as the latter slides, and a roller bearing between the top surface of said top roll bearings and the mill frame permitting planar sliding of said top roll bearings.

4. In a crushing mill, a feed roll, a discharge roll, and 'a top roll cooperating with said feed and discharge rolls,

stationary frame means at opposite ends of said rolls,

bearing means for the top roll, an hydraulic ram to apply pressure to the top roll bearings to press said roll toward 4the feed roll, means to mount said bearing means slidably to permit tilting movement of the top roll axis toward and fromsaid feed roll, and means to support said bearing means for pivotal movement about an axis perpendicular to the plane of top roll tilting, said pivotal supporting means for the bearing means being spaced from the axis of said hydraulic ram.

5. In a crushing mill, a feed roll, a discharge roll, and

-a top roll cooperating with said feed and discharge rolls,

bearing means for two of said rolls, means to mount said bearing means to permit tilting movement of the top roll .toward and from the feed roll and of the discharge roll toward and from the top roll, and means to support said bearing means for pivotal movement about an axis perpendicular to the plane of tilting of the roll which it supports, said pivotal supporting means for the bearing means being spaced from the axis of said hydraulic ram.

6. A crushing mill as claimed in claim 5 wherein the -bearing mounting means includes a block slidably mount- Vroll bearing means.

8. A crushing mill as claimed in claim 5 having aligner rolls between said pressure me'ans and said roll bearing means to avoid pinching and binding tof said bearings by said pressure means as the bearings move.

9. A crushing mill as claimed in claim 5 having aligner rolls between said pressure means land said top roll bearing means, one of said aligner rolls being perpendicularly askew nelative to the other.

l0. In a crushing mill, -a top roll, a feed roll and a (discharge roll, means yapplying pressure along lan axis to press the top roll toward the feed roll, means to press the discharge roll toward the top roll, means to mount the discharge roll for tilting of its taxis in a plane toward -and from the top roll, means to mount the top noll for 'tilting of its axis in the direction of the feed roll, the mounting means for said rolls including bearings, and means to support said top roll bearings for pivotal movement about an axis perpendicular to the plane lof `tilting said pivotal supporting means for the top roll bearing means being spaced from the `axis of the hydraulic riam.

11. In a crushing mill, a top roll, 'a feed roll and a vdischargeroll, means to mount the discharge roll for and means vto support said bearings for pivotal movement about an axis perpendicular to the plane of roll tilting and passing through the roll axis, land separate hydraulic pressure means for each bearing of said top and discharge rolls applying pressure individually to each bearing, said pressure means pressing the discharge roll toward the top roll and the top roll toward the feed roll, said pivotal supporting means for the top roll bearing means being spaced from the 'axis of the hydraulic ram.

12. A mill as claimed in claim 1l land aligner rolls between said pressure means and top roll bearing means, one of said aligner rolls being perpendicularly askew relative to the other.

13. In a crushing mill, a feed roll, a discharge roll, land a top roll cooperating with both said feed roll and said discharge roll, means to apply pressure to said top roll to press it toward said feed roll, and means to press said top and discharge rolls the one toward thfe other to squeeze material passing between them, land means to mount said top roll for tilting away from said feed roll independently of any movement of the discharge roll, said top roll mounting means including bearings, 'a rectilinearly slidable member supporting Ione of said bearings, and pivotal mounting means between that bearing and that member providing pivotal movement of that bearing relative to that member, said slidable member being spaced from the pressure axis.

14. A crushing mill as claimed in claim 13 having bearing moans for said discharge roll, means to mount one of said bearings for rectilinear movement toward said top roll, and 'a pivotal mounting for said bearing on said mounting means providing for pivotal movement of said bearing relative to said mounting means.

15. A crushing mill as claimed in claim 14 having aligner rolls between said pressure `applying means and said bearings providing free movement of said bearing means rellative to said pressure applying means at the point of contact thereof.

References Cited in the le of this patent Y UNITED STATES PATENTS OTHER REFERENCES International Sugar Journal, May 1954, vol. LVI, No. 665, pages 129-131.

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