AU615281B2 - Impeller bar installation and repositioning means for impact crushers having "open" type rotors - Google Patents

Description

Fee: $150.00 I- -I- ~~a9 -1 COMMONWEALTH OF AUSTRALIA D 7528 1 FUIVIl ±U PATENTS ACT 1952 r n Ir P T. T V P T T T A T T On v v ,L Y LS P E C I F I C A T I 0 N FOR OFFICE USE: Class Int.Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: 0 Name of Applicant: t t 'Address of Applicant: Actual Inventor: CEDARAPIDS, INC.

916 Sixteenth Street, Cedar Rapids, Iowa 52402, United States of America David A. Ostergaard Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney Complete Specification for the Invention entitled: "IMPELLER BAR INSTALLATION AND REPOSITIONING MEANS FOR IMPACT CRUSHERS HAVING "OPEN" TYPE ROTORS" The following statement is a full description of this invention, including the best method of performing it known to us:- 1 i.

i. or uociaranil (q mno seal, witness or legalisation).

To THE COMMISSIONER OF P/ (Signature of Declarant) ATENTS. Vernon L. Schrimper Executive Vice President CEDARAPIDS, INC.

Ihih i i* J u; -I ;I~ rla IMPELLER BAR INSTALLATION AND REPOSITIONING 00 MEANS FOR IMPACT CRUSHERS HAVING "OPEN" TYPE 0 00 ROTORS S0000 00 a 0 0 Impact crushers of the impeller type typically utilize a rotor having several axially extending impeller bars C C t t t disposed in recesses about its periphery. The impeller bars strike the rock entering the crusher and hurl it against one 5 or more sets of breaker bars in the process of reducing the I S.

rock to size. From time to time the impeller bars, since they Gllr are abraded by the rock, must be adjusted to compensate for wear and then finally replaced which in turn requires that they c be removably attached to the rotor. At the same time the 10 attachment must be mechanically secure and rigid enough for the bars to withstand the rapid and repeated blows with which they strike the rock.

The prior art abounds with schemes for removably affixing impeller bars to their rotors. The most prevalent, it seems, employ wedges of various configurations and functions, whether the rotors themselves are of the "solid" cast type or of the "open" type consisting of several axially spaced i I

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_r Id 2 discs. Generally speaking, the wedges in these instances act in one of two ways: either radially of or axially of the rotor. But in varying degrees all of the foregoing suffer from one or more of the following: complexity, weight, poor accessibility for inspection, adjustment or replacement, high manufacturing costs, and "liming" which increases the difficulty of adjustment or replacement.

o °o It is an object of the present invention to provide a oo000o 0oo00° rotor assembly for an impact crusher which will avoid or at o 00 .0oo" least ameliorate the above discussed disadvantages of the 00 0 o 0 0 o *0 prior art.

0 0 0 0 According to the invention there is provided a rotor assembly for an impact crusher, the rotor having a rotational axis and at least one pair of axially spaced rotor discs 0 000000oooo 0 0 extending radially of the rotor assembly with respect to said 0000 axis, the discs having axially aligned sets of recesses D 00 00 transversely therethrough and equally spaced thereabout, the recesses extending generally radially inwards from the periphery of each disc, each disc recess having a pair of 0o°" opposed first and second spaced side walls and a radially inner end wall extending transversely of the disc, an axially extending impeller bar disposed in each disc recess, each impeller bar having first and second opposite, outward facing side walls, the bar first side wall being in opposed spaced relation to the disc recess first side wall, the disc recess I and bar first side walls converging towards each other in a I generally radially outwards direction, and first means V

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0 0 0000 o 0 o 00 o0 o 000 00 0 0 0 0 00 00 00 0 o o S0f0 0 0 0 00 o o0 0 0Bo oo o O 0 00 0 D 0 0 00 2a operative between the disc recess and bar first side walls and second means operative between the disc recess and bar second side walls for retaining each impeller bar in its respective disc recess, the first retaining means for each disc recess including: first and second wedges, the first wedge being disposed between the disc recess and bar first side walls and movable therebetween in a generally radially outwards direction into wedging engagement with the disc recess and bar first side walls, the first wedge having a radially inner end wall in spaced opposed relation to the adjacent disc recess end wall, the disc recess and first wedge end walls converging towards each other in a direction transversely of the disc, the second wedge being disposed between the disc recess and first wedge end walls and movable therebetween in a direction transversely of the disc into wedging engagement with the disc recess and first wedge end walls, and means operative between the disc and the second wedge to urge the second wedge in said transverse direction and thereby the first wedge in said outward direction.

In a preferred embodiment the wedging arrangement employs a pair of wedges removably securing each impeller bar to its respective rotor disc. Each pair of wedges consists of a first wedge acting radially of a rotor disc between the side wall of a recess in the disc and the leading face of the impeller bar, and a second wedge acting axially of the disc between the radially inner end wall of the recess and the radially inner end of the first i

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2b wedge. The latter end of the first wedge is provided with a wedging face which mates with a cooperating wedging face on the second wedge, the latter wedge being urged against the first wedge by a bolt axially through the second wedge, on the one hand, and an anchor plate and nut operative against one face of the rotor disc, on the other hand.

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6 .O The parts involved are simple, relatively light in 0000 0oooo weight, easily manufactured, and readily accessible either o0 0 0 0 00 0 for 0 0 0 0 00 0 0 0 0 0 00000 o00 0 00 0 00 0 0 f 00 0 0 00 00 0 0 0 0

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ia .y 1 Nh r aa~~t I, a^ r> ;1 -3inspection or for adjustment or replacement of the impeller j bars on account of wear. Liming between the parts is quickly broken by a few hammer blows once the bolts through the second wedges are removed. Each impeller bar is provided with a hole through it from side to side at its center of gravity so that the bar can be lifted onto the rotor by a hook. When the bar is later to be repositioned to compensate for wear, the hook lifts the bar from the rotor and allows it while suspended to be rotated on or by the hook before being reinstalled in a new 10 position on the rotor. Other features and advantages of the present invention will become apparent from the drawings and the more detailed description which follows.

c Figure 1 is an end view of an "open" type rotor of an impact crusher illustrating the installation of the impeller bars according to the invention, one set of bars being omitted t in order to depict the configuration of one of the recesses in the rotor discs.

c tS Figure 2 is a sectional view of the rotor taken along the line 2-2 of Figure 1.

Figure 3 is a sectional view taken along the line 3- 3 of Figure 1.

Figure 4 is a perspective view of a portion of the rotor of Figure 1 showing the installation at the outer end of one of the breaker bars.

Referring first to Figures 1 and 2, the rotor 10 consists of a number of discs 11 equally axially spaced along a cylindrical tube 12 to which the discs 11 are welded. The tube -4- 12 is counterbored at each end into which are fitted a pair of hubs 13 having flanges 14 bolted at 15 to the two end-most discs 11, whence the rotor 10 revolves about the axis of the tube 12 and hubs 13. The discs 11 are provided with four sets of axially aligned recesses 16 equally spaced about their peripheries. It will be understood, of course, that the recesses 16 could be greater or fewer in number without affecting the endeavor of the invention. Each recess 16 extends generally radially inwards and, with respect to the direction of 0 10 rotation indicated by the arrow in Figure 1, includes a leading 0040 side wall 16a, an opposing trailing side wall 16b and an end wall 16c of the spacing and configuration shown at the left in Figure 1, the trailing side walls 16b having a greater radial extent than the leading side walls 16a. Adjacent their outer ends the trailing side walls 16b of each set of recesses 16 are circularly relieved to partially encompass a cylindrical backup bar 17 welded to the discs 11.

Each set of disc recesses 16 in turn receives a pair of impeller bars 18 disposed end-to-end, each impeller bar 18 being rectangular in plan but slightly trapezoidal in crosssection for casting purposes. Each bar 18 is cast with an axially extending, shallow seat 19 in its leading side wall 18a midway between its radially inner and outer ends (see Figures 1 and 2) and concentric with the back-up bars 17. The trailing side wall 18b of each impeller bar 18, which is parallel to the leading side wall 18a, is cast with a pair of similar, radially spaced seats 20a, 20b, the outer seat 20a of each bar 18 receiving the back-up bar 17 when the impeller bars 18 are initially installed, as shown in the drawings. In that posi- d tion the radially inner portions of the bar side walls 18b abut the radially inner portions of the recess side walls l1b and the recess side walls 16a and the bar side walls 18a converge towards each other in a radially outward direction. The outer axial ends of each pair of impeller bars 18 overhang the outboard faces of the two end discs 11, as shown in Figures 2 and 4, each end of the bars 18 being provided with a pair of opposite, radially elongated insets 21 having axially inner faces 10 21a flush with the outer faces of the discs 11 (see Figures 2 00 and The impeller bars 18 are held against axial movement S o by retainer blocks 22 overlapping the discs 11 and the bar *0 0 0 inset faces 21a, the blocks 22 being counterbored to encompass the heads of bolts 23 securing the blocks 22 to the axial end faces 17a of the back-up bars 17 (see Figures 2 and Each impeller bar 18 is also provided with a circular hole 24 (see Figure 2) from its side wall 18a through its side wall 18b and *ttc located at its center of gravity, that is to say in this case, at the geometrical centers of the side walls 18a, 18b, all for 20 the purposes to be described.

As previously noted each impeller bar 18 is clamped to the discs 11 by a pair of wedges disposed in the recesses 16 of each disc 11. The first wedges 25 act radially outwards between the converging recess side walls 16a and impeller bar side walls 18a, the wedges 25 having wedging faces 25a (see Figure 2) operative along the recess side walls 16a and wedging faces 25b (see Figure 3) operative along the impeller bar side i walls 18a. The wedges 25 are axially retained in position by iI ,ill .i.

'|1 Li 4 partial lips 26 (see Figures 2, 3 and 4) which straddle the faces of the discs 11, the wedges 25 extending radially inwards of the lips 26 and provided at their radially inner ends with I transverse wedging faces 25c (see Figures 2 and The second wedges 30 act axially between the recess end walls 16c and the ij faces 25c of the first wedges 25, the wedges 30 having wedging faces 30a operative across the recess end walls 16c and wedging faces 30b (see Figures 2 and 3) cooperating with the faces of the first wedges 25. The wedges 30 are urged axially of the 0410 discs 11 by axially directed, headed bolts 31 through the wedges 30 and anchor plates 32 overlying the faces of the discs 11 at the converging ends of the disc recess end walls 16c and the faces 25C of the first wedges 25. When nuts 3 3 at the other ends of the bolts 31 are tightened, axial movem~ent of the wedges 30 forces the wedges 25 radially outwards by virtue of the cooperating wedging faces 25c and 30b. Belleville washers 34 (see Figure 3) are preferably interposed between the plates A 32 and nuts 33 to maintain tension on the wedges 30 in all events. Hence the impeller bars 18 are held securely in position between the disc recess side walls 16b and the back-up bars 17 on the one hand, and the wedges 25 on the other hand.

Note that the wedges 25 and 30 are sirrple in structure and of 4 relatively light weight. They are eusily manufactured inasmuch as tolerances are not critical since the wedges 30 at all times act positively on the wedges 25 and the bolts 31 and anchor Plates 32 in turn on the wedges 30. Cracking, breakage or loosening of any of the wedges 25 or 30 can also be readily observed during routine inspection of the rotor 10. Should the

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Ir -7wedges 25 and 30 loosen for some reason, the retainer blocks 22 will prevent the impeller bars 18 from moving axially and striking the end walls (not shown) of the housing about the rotor On 00 o 00 00 0 0900 0 09 0 0 o 00 0 00 00 0 0 000 Q0 0 ao 0 O 00 Ci i; I i~ f r a: i.:

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Claims (8)

1. A rotor assembly for an impact crusher, the rotor having a rotational axis and at least one pair of axially spaced rotor discs extending radially of the rotor assembly with respect to said axis, the discs having axially aligned sets of recesses transversely therethrough and equally spaced thereabout, the recesses extending generally radially inwards from the periphery of each disc, each disc recess having a pair of opposed first and second spaced side walls and a radially inner end wall extending transversely of the disc, an axially S Q side walls, the bar first side wall being in opposed spaced o0 o. relation to the disc recess first side wall, the disc recess 4 and bar first side walls converging towards each other in a I 15 generally radially outwards direction, and first means opera- tive between the disc recess and bar first side walls and second means operative between the disc recess and bar second side walls for retaining each impeller bar in its respective disc recess, the first retaining means for each disc recess I ,20 including: first and second wedges, the first wedge being S*'4 disposed between the disc recess and bar first side walls and movable therebetween in a generally radially outwards direction into wedging engagement with the disc recess and bar first side walls, the first wedge having a radially inner end wall in spaced opposed relation to the adjacent disc recess end wall, i the disc recess and first wedge end walls converging towards I 1 each other in a direction transversely of the disc, the second wedge being disposed between the disc recess and first wedge 4r V:*il^ ino wdgin enagemnt ith he isc eces an ba firt sde |km als h irtwde aigarailyine n wl n| tive between the disc recess and bar first side walls and second means operative between the disc recess and bar second i 1 ,I, W -9- end walls and movable therebetween in a direction transversely of the disc into wedging engagement with the disc recess and first wedge end walls, and means operative between the disc and the second wedge to urge the second wedge in said transverse direction and thereby the first wedge in said outward direction.

2. The rotor assembly of claim 1 wherein the second 5' impeller bar retaining means for each disc recess includes ooQ o means interlocking the disc recess and bar second side 0o6o walls effective to restrain radially outward movement of 6 oa the bar when the first and second wedges are in said 00 0 wedging engagement.

3. The rotor assembly of claim 1 or claim 2 wherein the urging means for the second wedge comprises a plate Ldisposed adjacent the converging ends of the disc recess and first wedge end walls and overlapping the disc, a 00 headed bolt extending transversely of the disc through the plate and the second wedge, and a nut on the other end of the bolt.

4. The rotor assembly of claim 2 or claim 3 wherein the second impeller bar retaining means comprises complementary reliefs in the disc recess and bar second side walls and an impeller bar retainer member disposed therein and secured to the disc, said reliefs and retainer member extending axially of the disc, and wherein said wedging engagement of the first and second wedges f maintains said relief in the impeller bar in engagement with the retainer member.

L' k 0So\u\^^* J 'k i^A B~sa 1~ ~I a a L PF T i~i ii ;I r 00 cc o ot 0000 0 0000 o wo cc C 0040( 04 i 0 0 00 00 00 00 0 0 S 14 400 1 0 0000r 0 40 40 0 O 1r 0 i 0 000 0 000000 O 0 it O 0 II I 0(I 10 The rotor assembly of claim 4 wherein each impeller bar includes an axial end face extending transversely of said first and second side walls thereof and disposed adjacent an outer axial face of one of the rotor discs, and including third retaining means operative between said axial end face of the bar and said outer face of the disc effective to restrain movement of the impeller bar in one axial direction relative to said disc, the third retaining means being in addition to said first and second retaining means.

6. The rotor assembly of claim 4 or claim 5 wherein each of said impeller bar retaining members includes an axial end face adjacent said axial end face of the bar and said outer face of the disc, and wherein the third retaining means includes a block secured to said axial end face of the impeller bar retainer member and engaging said axial end face of the bar and said outer face of the disc.

7. The rotor assembly according to any one of the preceding claims including third impeller bar retaining means operative between at least one of the rotor discs and each impeller bar effective to restrain movement of the impeller bar axially of the rotor assembly, the third retaining means being in addition to said first and second retaining means.

8. A rotor assembly substantially as herein described with respect to Figure 1 of the accompanying drawings. DATED this 21st Day of May, 1991 CEDARAPIDS, INC. Attorney: LEON K. ALLEN of" tilte o' F ct ALX'rn, o Aus~OrWtviL: of SHELSTON\ WATLLS 2