US2803411A - Segmental crusher roll - Google Patents

Description

H. c. POLLITZ SEGMENTAL CRUSHER ROLL Filed Oct. 17, 1955 Aug. 20, 1957 I ZVZ EMZEF HAROLD C RuL/rz ZSQSAH Patented Aug. 20, 1957 SEGRIENTAL CRUSlER HULL Harold C. Pollitz, Cedar Rapids, l'owa, assignor to Iowa Manufacturing Company of Cedar Rapids, lows, Qedsr Rapids, Iowa, a corporafion of Iowa Application October 17, 1955, erial No. 54%,905

2 Claims. (Cl. 241294) The present invention relates to the construction of rolls adapted for use in roll type rock Crushers and the like. More particularly, the present invention is concerned with the provision of a novel and substantially improved crusher roll having its periphery formed of a plurality of impact resisting metal segments secured to a cylindrical core by means of radially extending wedge bolts.

As those familiar with the art of roll crusher construction are aware, numerous attempts have been made at the construction of a simple yet strong crusher roll for use in the reduction of stone and other similar frangible materials. I am, of course, aware of the fact that such attempts have included the utilization of replaceable roll segments secured to a central cylindrical core or hub. However, to my knowledge none of the previously constructed crusher rolls of the segmental type have satisfactorily provided complete alignment between the segments and the core in a simple manner. Further, in the segmental rolls with which I am familiar the constant impacts have a tendency to cause a loosening action on the means securing the segments to the core with the result that continued operation of the device causes fatigue of the roll components and ultimate failure. Since it is practically impossible to detect a loose segment during crushing operations, as a result of the noise caused by the reduction of the rocks it is of the utmost importance that satisfactory means be provided for absolutely preventing inadvertent loosening of the segments under crushing vibrations.

In accordance with the principles of the present invention a crusher roll is provided having a one-piece hub or core carrying a plurality of peripheral segments secured thereto by means of radially extending securing bolts. The securing bolts have a wedging relationship with the segments and the outer ends thereof lie flush with the peripheral surface of the crushing segments. The inner ends of the bolts are rigidly secured to an axially projecting peripheral flange on the core thereby rigidly securing, and simultaneously locating, the individual segments to the peripheral surface of the core. A further peripheral interlocking rib and recess are provided between the inner surface of the individual segments and the external peripheral surface of the core to provide positive axial alignment between the segments and the core during assembly thereof.

In accordance with the principles of the present invention the segments of the crushing roll are constructed of extremely hard heat treated abrasion resistant alloy steel, cast steel having a high percentage of manganese, or other suitable hard, wear resisting material. The wedging bolts are constructed with shanks of heat treated steel and preferably have the extreme head ends constructed of hard metal similar in wear characteristics to the material of the segments. The heat treated bolt may, accordingly, be tightened to extreme tightness without permanent deformation while at the same time retaining sufficient elasticity under the tightening load to prevent loosening under the extreme vibrations produced by the normal crushing operation.

It is, accordingly, an object of the present invention to provide a novel and substantially improved segmental crushing roll.

Another object of the present invention is to provide novel and substantially simplified means for securing peripheral segments of a crushing roll to the core thereof.

Still a further object of the present invention is to provide an improved means for securing segments of a crushing roll to the core thereof in substantially perfect axial and circumferential alignment.

A feature of the invention resides in the utilization of radially extending securing bolts having tapered head portions for wedging contact with crushing roll segments and for tightening from a point within the crushing roll.

Another feature of the invention resides in the utilization of a plurality of peripheral segments secured to a crushing roll core by means of a plurality of annular rows of radially extending bolts having their heads flush with the outer peripheral surface of the roll segments making it unnecessary to remove the crushing rolls from the crusher for replacement of a roll shell.

Still other and further objects and features of the present invention will at once become apparent to those skilled in the art from a consideration of the attached drawings wherein one embodiment of the present invention is shown by way of illustration only, and wherein:

Figure l is a side elevational view of a segmental crushing roll constructed in accordance with the principles of the present invention; and

Figure 2 is a cross sectional view of a crusher roll constructed in accordance with the principles of the present invention and taken along the line lIIl.

As shown on the drawings:

As may be seen from a consideration of Figures 1 and 2 of the drawing, the crusher roll of the present invention comprises a core 16 keyed for rotation with a supporting shaft 11 by means of a key 12. Segments 13, 14 and 15, each comprising approximately 120 of the outer circumference of the roll are secured to axially projecting peripheral flanges 16 and 17 of the core 10 by means of annular rows of radially extending bolts generally indicated at 29.

Each of the bolts 26 is provided with a shank 21 and a tapered head portion 22 which cooperates with a tapered hole 23 in the respective segments. As may be seen from Figure 2, the segment holes 23 are positioned in radial alignment with the somewhat larger holes 24 in the core or hub 1d. The holes 24 are slightly radially outwardly tapered and are somewhat larger in diameter than the cylindrical portion 23a of the holes 23 in order to eliminate any possibility whatever of the tapered portions 22 of the bolts 20 from bottoming against the outer periphery of the core 10 before the respective segment is tightly secured thereto. In view of the slight clearance between the holes 24 and the shank 21, alignment of the segments 13, 14 and 15 relative to the core 1%) is supplemented by the annular rib 25 which cooperates with an arcuate slot 26 in each of the segments.

During assembly, the individual segments, such as for example segment 13, are positioned in place on the periphery of the core 1% with the rib 25 seated in the slot 26. The individual bolts 26 are then passed through the aligned holes 23 and 24 and nuts 27 are threaded into a snug position permitting the segment 13 to seat evenly throughout its portion of the circumference of the core Preferably, all of the segments are thus snugly secured before any of the nuts 27 are tightened into their final tight condition. Upon assembly of the segments to the core, the individual nuts 27 are tightened into their final tight condition, preferably by tightening diametrically opposed nuts in sequence. While such a tightening procedure is preferred, in order to maintain the surface of the roll in a perfectly circular form it will be understood that varioustightening, sequences-may be utilized without departing from the scope of the present invention. After the. nuts .27 have been ,tightened into their final condition, lock nuts 28 are threaded into tight engagement therewith to provide a completely assembled unit.

As may be seen from Figure 2, the tapered head portions 22 of the bolts 20 have a taper angle approximating 20 thereby providing tight wedging cooperation between thehead-22 and its respective hole 23. This relatively small taper provides sufficiently tight wedgi'ng action to prevent rotation. of the bolt 2% during tightening of the nuts 27 and prevents any rotation thereof during operation of the roll during rock crushing. The shanks 21 of the bolts. 2tv are preferably constructed of a heatrtreated steel. having a high elastic limit so that an extreme torque may be applied to the nuts 27 during the tightening operation without exceeding the yield point of the metal. Under such a. construction, the resiliency of the metal in the bolt shanks 21 will provide a constant force tending to prevent rotation of the nuts 27 in the loosening direction and accordingly, in view of the non-rotatability of the bolt head 22, it. has been found that the roll segments of the present invention maintain their rigid association with the core 16) through long periods of hard usage. While self-loosening of the bolts 2%} is, therefore, substantially impossible, it will be readily apparent that the crusher roll of the present invention may readily be disassembled by striking the individual securing bolts 2%} from the inner ends thereof with a soft metal hammer or the like after loosening the nuts 27 and 28. In this manner, damaged segments may readily be replaced.

The individual segments 13, 14- and 15 are preferably constructed of an abrasive resistant, hard material, such as for example cast steel having a relatively high manganese content, such as for example on the order of 12% to 14%. This material is admirably suited to crusher rolls, especially when supported by a plain cast steel core such as that shown at 19. The individual bolts 2% are likewise preferably provided with ends 22a constructed of a material having extreme abrasion resistance and impact resistance. This material may be welded to the remainder of the bolts, by means of resistance welding or similar operation before the tapered portion of the head 22 is machined. As a result of the extreme wear resistance of the end portion 22a of the bolt 20 deterioration thereof during crushing is prevented andat the same time the extreme toughness and resiliency of the heat treated shank portion of the bolt prevent any tendency to become loose. One material that has proven satisfactory for use in the end portions 22a is the material commercially known as Stoodite, a hard ferrous alloy containing approximately 35% chromium.

it will, of course, be apparent to those skilled in the art that variations and modifications may be made relative to the structure hereinabove set forth without departing from the scope of the novel concepts herein disclosed. Accordingly, it is my intention that the scope of the present invention be limited solely by that of the hereinafter appended claims.

I claim as my invention: 1. A crusher roll comprising a core having a peripheral surface with a plurality of radially extending bores therein, an arcuate segment having a contour cooperating with said surface and being constructed of extremely hard, wear resisting material, a vplurality of radial bores in said segment for alignment with said surface bores, each of said segment bores having a radially outwardly clearing taper, means for aligning and securing said segments to said core comprising a bolt for each of said aligned set of bores, each said bolt having an enlarged tapered head for cooperation with said outwardly flared taper and a shank extending inwardly of said peripheral surface for cooperation with a retaining member, said bolt head having its external surface constructed of hard Wear resisting material and its shank constructed of tough high tensile strength material whereby the outer surface of said roll is a continuous, hard wear resisting surface and whereby substantial stress may be applied to said bolt shank to maintain said segment under tension against said peripheral surface, said means for aligning and securing said segment to said core additionally comprising an annular peripheral rib on said core and a cooperating arcuate slot in said segment and each said bolt shank. having a diameter less than the diameter of the radially extending bores in said roll surface whereby said segment is axially aligned relative to said core and whereby the plurality of bolts passing through said arcuate segment may be evenly tightened in sequence and slight peripheral shift: ing of the segment may occur to provide evenly distributed stresses throughout the peripheral length of the arcuate segment.

2. A crusher roll comprising a core having a peripheral surface with a plurality of radially extending bores therein, an arcuate segment having a contour co-operating with said surface and being constructed of extremely hard, wear resisting material, a plurality of radial bores in said segment for alignment with said surface bores, each of said segment bores having a. radially outwardly clearing taper, means for aligning and securing said segments to said core comprising a bolt for each of said aligned set of bores, each said bolt having an enlarged tapered head for co-operation with said outwardly flared taper and a shank extending inwardly of said peripheralv surface for co-operation with a retaining member, saidbolt head having its shank constructed of tough high tensile strength material whereby substantial stress may be applied to said bolt shank to maintain said segment under tension against said peripheral surface, saidmeans for aligning and securing said segment to said core additionally comprising an annular peripheral rib on said core and a co-operating arcuate slot in said segment and each said bolt shank having a diameter less than the diameter of the radially extending bores in said roll surface Whereby said segment is axially aligned relative to said core and whereby the plurality of bolts passing through said arcuate segment may be evenly tightened in sequence and slight peripheral shifting of the segment may occur to provide evenly distributed stresses throughout the pe ripheral length of the arcuate segment.

References Cited in the file of this patent UNITED STATES. PATENTS Cushman July 21, 1874

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