Note: Descriptions are shown in the official language in which they were submitted.
CA 02216389 1997-09-24
ROTOR FOR ~3HREDDER8 AND U~Ml;',12~T~.T.
FIELD OF THB l~.v~.~lON
The present invention relates to rotors for shredders
and hammermills. In particular, the present invention
5relates to a rotor having a generally gapless imperforate
outer surface and providing full cutting action across an
axis of the rotor.
BACRGROUND OF THE l~.v~lON
10Hammermills and shredders are generally used for
crushing, shredding or breaking scrap metal and other
materials such as automobile bodies into small fragments or
pieces for recovery and reuse. Hammermills and shredders
typically include a housing, a rotor hammer assembly
15rotatably supported within the housing, and a drive
assembly for rotating the rotor hammer assembly past grate
bars of the housing to fragment and shred material
therebetween. Rotor hammer assemblies conventionally
comprise either a disk style rotor or a spider style rotor.
Disk style rotors generally consist of a rotor drive
shaft centered along an axis, a plurality of circular
plates fixedly secured to the drive shaft along the axis,
CA 02216389 1997-09-24
a plurality of hammer support rods extending parallel to
the axis through each plate, and a plurality of hammers
rotatably supported about the hammer support rods between
consecutive plates. To reduce wear of the plates which
support the hammer support rods and hammers, each plate is
typically provided with a cap or liner made of wear
resistant material and is positioned about the entire
circumferential perimeter of the plate. As a result, disk
style rotors are extremely durable and wear-resistant.
However, because disk style rotors require a plate between
each consecutive hammer for supporting the hammers, disk
style rotors inherently include gaps along the axis of the
rotor where material remains uncut by the hammers. As a
result of these gaps in the cutting action of the disk
style rotor, the feeding of material into the hammermill or
shredder is more difficult and shredding efficiency is
reduced.
Spider style rotors typically consist of a rotor drive
shaft, a plurality of multi-armed spiders fixedly secured
on the drive shaft, a plurality of hammer support rods
extending through the arms of the multi-armed spiders, and
a plurality of hammers rotatably supported about the hammer
support rods. Each hammer is positioned and supported by
radially aligned arms of every first and third consecutive
multi-armed spider between the arms of an intermediate
second spider. As a result, spider style rotors include at
least one hammer along the entire axis of the rotor to
provide full cutting action. Consequently, material feed
and shredding efficiency is improved. Although spider
style rotors achieve full cutting action along the rotor
axis, spider style rotors inherently include a multitude of
openings between the hammers and between the hammer rows.
These openings subject the spider style rotor to wear and
material clogging.
8 ~l2~RY OF THE lNV~;Nl lON
A rotor for shredders and hammermills includes a rotor
body having an outer cylindrical surface extending along an
CA 02216389 1997-09-24
axis, a plurality of axially spaced concavities defined on
the outer cylindrical surface and a hammer supported within
each concavity. The outer cylindrical surface has a convex
portion radially extending at least ninety degrees about
the axis. Each concavity is radially offset from an
adjacent concavity.
The invention is more specifically directed to a rotor
that includes a plurality of segments supported end-to-end
along the axis. Each segment includes a body configured
for rotation about the axis. The body has an outer
periphery or peripheral surface concentric with the axis.
The outer periphery includes a convex portion extending at
least ninety degrees about the axis and at least one
concave portion sized for at least partially receiving the
hammer. Preferably, the convex portion extends
approximately three hundred degrees about the axis while
the concave portion extends approximately sixty degrees
about the axis. The convex portion preferably includes at
least one wear cap partially extending about the axis to
define the convex portion.
According to one preferred aspect of the present
invention, each of the plurality of segments includes two
2S or less concavities. The plurality of segments are
arranged in a rotational pattern so as to statically and
dynamically balance the rotor. Preferably, for each first
concavity spaced from an axial center line of the rotor
body by a first distance on a first side of the center
line, the rotor body contains a second concavity radially
aligned with the first concavity and spaced from the axial
center line by the first distance on a second side of the
axial center line. For each first plurality of conca~ities
in radial alignment about the axis, the rotor body includes
a second plurality of concavities of equal number radially
spaced from the f irst plurality of concavitie8 by
approximately one hundred eighty degrees about the axis.
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In one preferred embodiment, the rotor body includes
a first concavity along the axial center line, a second
concavity along the axial center line spaced one hundred
eighty degrees from the first concavity and six consecutive
axial spaced concavities outwardly extending from each side
of the axial center line. Each outer consecutive concavity
is radially incremented by approximately sixty degrees.
The invention is also directed to a rotor liner system
for protecting the outer convex surface of the rotor from
wear. The liner system includes a plurality of individual
wear caps mating end-to-end and side-by-side about the
outer convex surface of the rotor. Each wear cap is
preferably reversible and interchangeable.
DETAILED DE8CRIPTION OF THE DRAWING8
Fig. 1 is a sectional view of a hammermill including
a rotor of the present invention.
Fig. 2 is a partially exploded schematic perspective
view of the rotor.
Fig. 3 is an exploded perspective view of intermediate
segments of rotor 12.
Fig. 3A is a schematic diagram illustrating an angular
pattern for the intermediate segments.
Fig. 3B is a schematic diagram illustrating an
alternative angular pattern for the intermediate segments.
Fig. 4 is a sectional view of the assembled rotor of
Fig. 2 taken along lines 4--4.
Fig. 5 is a cross sectional view of the rotor of Fig.
4 taken along lines 5--5.
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Fig. 6 is a cross sectional view of the rotor of Fig.
4 taken along lines 6--6.
DETAILED DE8CRIPTION OF THE PREFERRED EMBODIMENT
Fig. 1 is a sectional view of hammermill 10 including
rotor 12. Rotor 12 is a generally cylindrical body having
an axial length and being configured for rotation about a
generally concentric axis. Rotor 12 is rotatably supported
about the axis in a conventionally known manner and is
rotatably driven by a conventional rotary actuator or drive
mechanism. Rotor 12 generally includes hammers 13 which
extend about axis X and along the axial length of rotor 12.
Preferably, hammers 13 are each rotatably supported by
rotor 12 about individual axes encircling rotor axis X. As
a result, hammers 13 swing radially outward into engagement
with the material being shredded. Hammers 13 forcefully
engage material within hammermill 10 to crush and shred the
material for recovery and reuse.
Hammermill 10 feeds automobile bodies and other scrap
material to rotor 12 for shredding and conveys the shredded
fragments produced by rotor 12 for recovery and reuse. In
the preferred embodiment illustrated, hammermill 10
generally includes feed ramp 14, feed roller assembly 16,
and housing 18. Feed ramp 14 is a generally elongate chute
or slide upon which automobile bodies and scrap are fed to
rotor 12 by feed roller assembly 16.
Feed roller assembly 16 generally includes support 20,
upper feed roller 22, lower feed roller 24 and actuator 26.
Support 20 is an elongate structure configured for
rotatably supporting upper feed roller 22 and lower feed
roller 24 in engagement with automobile bodies and other
material being fed into hammermill 10. In the preferred
embodiment illustrated, support 20 is pivotably coupled to
feed ramp 14 by pivot 28. Actuator 26 is coupled to
support 20 so as to selectively pivot support 20, upper
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feed roller 22 and lower feed roller 24 about pivot 28 to
adjust the spacing between feed rollers 22 and 24 and feed
ramp 14 depending upon the size of the material being fed
into hammermill 10.
Upper feed roller 22 and lower feed roller 24 are
preferably rotatably driven by a drive mechanism (not
shown) above feed ramp 14 so as to engage and feed material
into housing 18 for being shredded by rotor 12. In
addition to feeding material into housing 18, feed rollers
22 and 24 crush the material prior to the material being
fed to rotor 12.
Housing 18 rotatably supports, encloses and cooperates
with rotor 12 to shred material fed to rotor 12. Housing
18 generally includes hood 34, cutter bar 38, lower grate
40 and upper grate 42. Hood 34 surrounds and encloses
cutter bar 38, lower grate 40 and upper grate 42. Hood 34
includes a plurality of walls which define an interior
chamber 44 extending about lower grate 40 and upper grate
42. Chamber 44 receives the smaller shredded material
which passes through lower grate 40 and upper grate 42.
Cutter bar 38 is a generally elongate anvil extending
along an entire axial length of rotor 12. Cutter bar 38 is
supported at a lower end of feed ramp 14 below feed rollers
22 and 24 and adjacent to rotor 12. As feed rollers 22 and
24 feed large scrap material between rotor 12 and cutter
bar 38, hammers 13 of rotor 12 cooperate with cutter bar 38
to shred the material. As rotor 12 continues to rotate,
rotor 12 carries the shredded material in a clockwise
direction across lower grate 40 and upper grate 42.
Lower grate 40 and upper grate 42 each comprise a
generally elongate rigid framework of bars arranged so as
to screen material being shredded by rotor 12. Lower grate
40 and upper grate 42 extend along the entire axial length
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of rotor 12 and are supported so as to cooperate with
hammers 13 to further shred and reduce the size of the
material being shredded by rotor 12. Once the material has
been sufficiently shredded by rotor 12, the material passes
through openings within lower grate 40 and upper grate 42
into chamber 44.
Although not illustrated, hammermill 10 additionally
includes a conventional conveying mechanism for removing
and carrying away shredded material from chamber 44 for
further processing. As conventionally known, hammermill 10
may also be provided with a suction hood or other
separating mechanisms for separating and removing light
weight particles such as plastics, dirt and foam from the
shredded material.
Figs. 2 and 3 schematically illustrate rotor 12 and
hammers 13 in greater detail. As best shown by Fig. 2,
rotor 12 generally includes intermediate segments 50a-50m,
end segments 52, drive shaft 54 and hammer support rods 56.
Intermediate segments 50a-50m form the substantially
imperforate body of rotor 12 for supporting hammers 13
while hammers 13 shred material. In the preferred
embodiment illustrated, intermediate segments 50a-50m
comprise generally cylindrical plates configured for being
supported end-to-end along rotor axis X to provide rotor 12
with its generally imperforate body. Each intermediate
segment 50a-50m includes a concentric bore 60, eccentric
bores 62 and a concavity 64. Concentric bore 60 coaxially
extends through each intermediate segment 50a-50m and
receives drive shaft 54. Eccentric bores 62 extend through
intermediate segments 50a-50m circumjacent to drive shaft
54 proximate the outer perimeter of each intermediate
segment 50a-50m. Eccentric bores 62 of intermediate
segments 50a-50m are aligned with one another and are also
aligned with eccentric bores 68 of end segments 52.
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Concavities 64 are cut-outs inwardly extending from an
outer periphery of each segment 50a-50m towards the center
of each segment 50a-50m. As a result, each intermediate
segment 50a-50m has a scalloped shape. Each concavity 64
is sized for at least partially receiving one of hammers
13. In the preferred embodiment illustrated, each
concavity 64 is radially offset from adjacent concavity 64
of adjacent segments 50a-50m. Concavities 64 receive
hammers 13 and enable rotor 12 to provide full cutting
action along rotor axis X while minimizing or eliminating
openings along rotor axis X to minimize wear and material
clogging.
End segments 52 (only one of which is shown in Fig. 2)
are generally cylindrical plates having an outer diameter
substantially equal to the outer diameters of intermediate
segments 50a-50m. End segments 52 each define concentric
bore 66 and eccentric bores 68. Concentric bore 66
concentrically extends through end segment 52 and is sized
for receiving drive shaft 54. Eccentric bores 68 extend
through end segment 52 at locations circumjacent concentric
bore 66. Eccentric bores 68 are preferably equidistantly
spaced about concentric bore 60 and drive shaft 54
proximate the outer perimeter of end segment 52. Eccentric
bores 68 receive hammer support rods 56 to carry hammer
support rods 56 about drive shaft 54 during rotation of
drive shaft 54.
Drive shaft 54 is an elongate rigid shaft extending
through and supporting end segments 52 and intermediate
segments 50a-50m of rotor 12. Drive shaft 54 extends
through concentric bore 66 of end segment 52 along rotor
axis X. Drive shaft 54 is rotatably driven by a drive
mechanism (not shown) to rotate rotor 12 about rotor axis
X.
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Hammer support rods 56 are elongate shafts or pins
extending through intermediate segments 50a-50m and hammers
13. Each hammer support rod 56 includes an end received
within an eccentric bore 68 of one of end segments 52.
Hammer support rods 56 couple intermediate segments 50a-50m
to end segments 52. In addition, hammer support rods 56
rotatably support hammers 13 about the axis of each hammer
support rod 56 along rotor axis X.
Upon assembly of rotor 12, end segments 52, drive
shaft 54 and hammer support rods 56 support and maintain
intermediate segments 50a-50m and hammers 13 together to
form an elongate compact and solid rotor body 69 for
supporting hammers 13 along rotor axis X. Along rotor axis
X, rotor body 69 contains two or less concavities 64 in any
one plane extending perpendicular to rotor axis X. In the
preferred embodiment illustrated, rotor body 69 contains a
single concavity 64 in any one plane extending
perpendicular to rotor axis X except for the plane
perpendicularly extending along the center line of rotor
body 69. As a result, the rotor body 69, thus formed,
minimizes the number of openings along its outer surface to
reduce wear, material clogging and impact damage.
Although rotor 12 is illustrated as including six
hammer support rods 56 supporting hammers 13 radially
offset from one another by approximately sixty deqrees,
rotor 12 may alternatively include a variety of alternative
configurations and arrangements. For example, rotor 12 may
alternatively include eight hammer support rods 56 for
supporting hammers 13 that are radially offset ninety
degrees from one another about rotor axis X. Various other
rotational patterns are also contemplate~ for providing
full cutting action along rotor axis X while minimizing or
eliminating openings or unfilled gaps about and along rotor
axis X.
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Although intermediate segments 50a-50m are illustrated
as being supported adjacent to one another by end segments
52, drive shaft 54 and hammer support rods 56, intermediate
segments 50a-50m may alternatively be supported or joined
S to one another by any one of a variety of alternative
assembly arrangements. Moreover, in lieu of rotor body 69
being formed from a plurality of intermediate segments 50a-
50m mounted adjacent to one another, rotor body 69 may
alternatively be formed as a single unitary body con~igured
for rotation about rotor axis X and provided with
concavities 64 for partially housing hammers 13.
Fig. 3 is an exploded perspective view schematically
illustrating intermediate segments 50a-50m and hammers 13
in greater detail. As best shown by Fig. 3, each
intermediate segment 50a-50m has an outer perimeter 70
extending in a plane perpendicular to rotor axis X. Each
outer perimeter 70 includes at least one convex portion 72
and at least one concave portion 74. Convex portions 72
and concave portions 74 of each individual segment 50a-50m
extend in a single plane perpendicular to rotor axis X.
When combined, the convex portions 72 and concave portions
74 of an individual segment 50a-50m extend three hundred
sixty degrees about rotor axis X to form outer perimeter
70.
Convex portions 72 extend about and define the
generally solid mounting structure of each intermediate
segment 50a-56m. In particular, convex portions 72 extend
circumjacent to eccentric bores 62 for supporting hammer
rods 56 (shown in Fig. 2). The degree to which convex
portions 72 extend about rotor axis X of each intermediate
segment SOa-50m is preferably maximized to reduce the size
and number of openings about rotor axis X where material
clogging and wear occur. In particular, each convex
portion 72 preferably extends radially about rotor aXis X
by at least about ninety degrees. Convex portions 72 of
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each segment 50a-50m preferably extend a combined total of
at least one hundred eighty degrees about rotor axis X.
For example, if a particular segment 50a-50m includes a
single concavity 64, the single convex portion 72 would
extend at least one hundred eighty degrees about rotor axis
X to provide the particular segment with at least a semi-
cylindrical configuration. In the preferred embodiment
illustrated, convex portions 72 of segments 50a-50f and
segments 50h-50m extend three hundred degrees about rotor
axis X. Convex portions 72 of segments 50g each extend one
hundred twenty degrees about rotor axis X and encircle
rotor axis X by a combined total of two hundred forty
degrees.
Concave portions 74 extend inwardly from convex
portions 72 towards concentric bore 60 and rotor axis X.
Each concave portion 74 extends inwardly from convex
portions 72 a sufficient distance such that the concavity
64 formed by concave portion 74 is sufficiently sized for
receiving a hammer 13. In the preferred embodiment
illustrated, concave portion 74 is a generally arcuate
shaped contour formed along perimeter 70 of each segment
50a-50m. Alternatively, concave portion 74 may have a
variety of other inwardly extending contours such as semi-
hexagonal, semi-octagonal, rectangular, triangular, and the
like. Furthermore, concave portions 74 may alternatively
comprise a linearly contoured cut-out so as to provide each
segment with a substantially semi-circular cross section.
As further shown by Fig. 3, segments 50a-50f and 50h-
50m are substantially identical to one another in that each
includes a single concavity 64. In contrast, segment 50g
includes a pair of opposite concavities radially spaced
approximately one hundred eighty degrees. Segment 50g is
centered between segments 50a-50f and 50h-50m. Preferably,
segment 50g is centered along an axial center line of rotor
12. In the preferred embodiment illustrated, concavities
CA 02216389 1997-09-24
12
64 of segments 50a-50m are preferably rotated about rotor
axis X in increments of approximately sixty degrees
relative to a preceding segment. As a result, each
concavity 64 of each segment 50a-50m is sandwiched between
and adjacent to convex portions 72 of adjacent segments
when stacked end-to-end to form rotor 12. For example,
concavity 64 of segment 50b is located between and adjacent
to convex portions 72 of both segments 50a and 50c. As a
result, each segment 50a-50m along rotor axis X includes at
least one hammer 13 to provide full cutting action along
rotor axis X. At the same time, however, the number of
inwardly projecting openings or unfilled gaps about and
along rotor axis X is reduced to reduce material clogging
and wear.
Figs. 3A and 3B illustrate patterns for arranging
intermediate segments 50a-50m so as to provide full cutting
action along the entire rotor axis X while statically and
dynamically balancing rotor 12 to reduce vibration and
other undesirable forces. In particular, each vertical
column represents a single intermediate segment 50a-50m.
Each horizontal row represents sixty degrees about rotor
axis X. Each capital letter represents a concavity 64
defined by a particular segment 50a-50m and angularly
positioned about rotor axis X.
Fig. 3A graphically illustrates the arrangement of
intermediate containers 50 presented in Fig. 3. As best
shown by Fig. 3A, segments 50a, 50g and 50m each include
concavities A in angular alignment with one another and
equidistantly spaced from the axial center line of rotor
12. In particular, the concavities of segments 50a and 50m
are equidistantly spaced from the center most segment 50g
and the axial center line of rotor 12. Segments 50f and
50h include concavities B in angular alignment with one
another and equidistantly spaced from the center line Of
rotor 12. Segments 50e and 50i, 50d and 50j, 50c and 50k,
CA 02216389 1997-09-24
and 50b and 501 similarly include concavities C, D, E, and
F, respectively, in angular alignment with one another and
equidistantly spaced from the center line of rotor 12. To
balance rotor 12, segment 50g additionally includes a
second concavity D angularly spaced one hundred eighty
degrees from concavity A. As illustrated by Fig. 3A, for
each concavity spaced from the axial center line of rotor
12 by a first distance on a first side of the center line,
rotor 12 includes a second concavity radially aligned with
the first concavity and spaced from the axial center line
by the same distance on a second side of the axial center
line. Furthermore, for each plurality of concavities in
radial alignment about the axis, rotor 12 includes a second
plurality of concavities of equal number radially spaced
from the first plurality of concavities by approximately
one hundred eighty degrees about the axis.
Fig. 3B graphically illustrates an alternative
rotational pattern of intermediate segments 50a-50m for
statically and dynamically balancing rotor 12. As shown by
Fig. 3B, segment 50g includes concavities A and D extending
along the axial center line of rotor 12 and radially spaced
one hundred eighty degrees apart from one another.
Segments 50f and 50h include a first pair of concavities B
spaced from the axial center line of rotor 12 by a first
distance and radially offset from concavity A of segment 50
by approximately sixty degrees. Segments 50e and 50i
include a second pair of concavities D spaced from the
axial center line of rotor 12 by a second distance greater
than the first distance and radially offset from concavity
A of segment 50 by approximately one hundred eighty
degrees. Segments 50d and 50j include a third pair of
concavities F spaced from the axial center line of rotbr ~2
by a third distance greater than the second distance and
radially offset from concavity A of segment 50g by
approximately three hundred degrees. Segments 50c and 50k
include a fourth pair of concavities C spaced from the
CA 02216389 1997-09-24
axial center line of rotor 12 by a fourth distance greater
than the third distance and radially offset from concavity
A of segment 50 by approximately one hundred twenty
degrees. Segments 50b and 501 define a fifth pair of
concavities E spaced from the axial center line of rotor 12
by a fifth distance greater than the fourth distance and
radially offset from the first concavity A of segment 50g
by approximately two hundred forty degrees. Lastly,
segments 50a and 50m include a sixth pair of concavities A
spaced from the axial center line of rotor 12 by a sixth
distance greater than the fifth distance and in radial
alignment with concavity A of segment 50g. Although Figs.
3A and 3B illustrate two such angular patterns for
intermediate segments 50a-50m, various other angular
patterns for intermediate segments 50a-50m are contemplated
depending upon the exact configuration and number of
intermediate segments 50.
Figs. 4-6 illustrate rotor 12 in greater detail. In
particular, Fig. 4 is a sectional view of assembled rotor
12 taken along lines 4--4 of Fig. 2. Fig. 5 is a cross
sectional view of rotor 12 taken along lines 5--5 of Fig.
4. Similarly, Fig. 6 is a cross sectional view of rotor 12
taken along lines 6--6 of Fig. 4. As best shown by Fig. 4,
drive shaft 54 extends through opposite sides of hood 34
and includes exterior threaded ends 80 for threadably
receiving nuts 82. Nuts 82 thread about ends 80 of drive
shaft 54 to axially secure intermediate segments 50a-50m
and end segments 52 against one another and along drive
shaft 54. Intermediate segments 50a-50m and end segments
52 are keyed to drive shaft 54 to radially secure
intermediate segments 50a-50m and end segments 52 about
drive shaft 54. As illustrated by Figs. 4-6, intermediate
segments 50g-50m and end segments 52 are further optionally
interconnected by tie rods 83 extending through eccentric
bores 84 and secured by nuts 85 for added strength.
CA 02216389 1997-09-24
As best shown by Figs. 4-6, each intermediate segment
50a-50m preferably includes a disk or hammer support 86 and
at least one exterior wear liner or cap 88. Hammer support
86 is a generally circular disk configured for being
fixedly secured about drive shaft 54 in an end-to-end
relationship with adjacent supports 86. In the preferred
embodiment illustrated, support 86 includes generally flat,
planar front and rear faces which butt against faces of
adjacent supports 86. Alternatively, supports 86 may be
provided with other mating configurations such as
corresponding male and female facial surfaces. As shown by
Figs. 5 and 6, each support 86 defines at least one
concavity 64. Each support 86 further defines concentric
bore 60 and eccentric bores 62 through which drive shaft 54
and hammer support rods 56 are inserted.
Wear caps 88 are generally wear-resistant liner
members configured for extending about and covering an
outer portion of hammer supports 86. As best shown by
Figs. 5 and 6, each segment 50a-SOm preferably includes 5
wear caps 88 extending about hammer support 86 to define
convex portion 72. Each wear cap 88 arcuately extends
about rotor axis X by approximately sixty degrees.
Alternatively, each wear cap 88 may arcuately extend about
rotor axis X by greater than or less than sixty degrees
thereby decreasing and increasing, respectively, the number
of wear caps 88 necessary to line or cover the entire
convex portion 72 of each intermediate segment 50a-50m.
Wear caps 88 protect hammer supports 86 from wear while
rotor 12 shreds material.
In the preferred embodiment illustrated, hammer
supports 86 and wear caps 88 are specifically configured to
form a mechanical interlock to securely support wear caps
88 relative to hammer supports 86. As best shown by Figs.
4-6, hammer supports 86 preferably define inwardly
extending grooves 90 configured and sized for partially
CA 02216389 1997-09-24
receiving wear caps 88 to form a mechanical interlock.
Wear caps 88 are generally elongate arcuate T-shaped
members including an inwardly extending tongue portion 94
and an arcuately extending liner portion 96. Tongue 94
extends generally perpendicular to liner portion 96 into
groove 90. Tongue 94 defines a bore 9 8 extending through
tongue 94. Bore 98 iS sized and located for receiving
hammer support rod 56. As a result, upon assembly of rotor
12, hammer support rods 56 project through bores 98 of wear
caps 88 to reliably secure wear caps 88 to hammer supports
86. Alternatively, wear caps 88 may be secured to hammer
supports 86 by a variety of other alternative mounting
arrangements.
Liner portions 96 O~ wear caps 88 extend generally
perpendicular to tongues 94 and are sized for extending
over the outer peripheral surfaces of hammer supports 86 to
protect hammer supports 86 from wear. As shown by Figs. 5
and 6, liner portions 96 of wear caps 88 mate end-to-end
about the outer peripheral surfaces of hammer supports 86.
As shown by Fig. 4, liner portions 96 of wear caps 88 also
mate side-by-side along rotor axis X and about the outer
peripheral surfaces of hammer supports 86. As a result,
wear caps 88 fully cover and protect the outer convex
surface of rotor 12 from wear in both circumferential and
axial directions. Because wear caps 88 mate end-to-end and
side-by-side about the outer convex surface of rotor 12
they provide rotor 12 with a constant outer radius. This
constant outer radius minimizes abrasive wear and impact
damage by eliminating corners or irregularities which would
otherwise take direct hits from large bales or pieces of
scrap. The constant outer radius also provides a smooth
surface which prevents the accumulation or wedging of
scrap. Because liner portions 96 of wear caps 88 mate
side-by-side along rotor axis X, wear caps 88 eliminate
gaps to prevent scrap from impacting on hammer supports 86
and from wedging between adjacent wear caps 88.
CA 02216389 1997-09-24
In addition to better protecting hammer supports 86 of
rotor 12, the rotor liner system formed by wear caps 88 is
simple and economical to produce, assemble and maintain.
As illustrated by Figs. 4-6, each wear cap 88 is
interchangeable with other wear caps 88 and fits every
position along and about rotor axis X of rotor 12. Because
the rotor liner system formed by wear caps 88 requires only
a single wear cap design, the rotor liner system has
reduced pattern, tooling and manufacturing costs.
Assemblage and maintenance are also simplified due to the
single capped design. As further shown by Figs. 4-6, due
to each wear cap's generally symmetrical design, each wear
cap is reversible. Wear caps 88 positioned adjacent hammer
pockets, such as concavity 64, generally wear at a higher
rate along the hammer pockets. Because wear caps 88 are
generally reversible, however, the useful life of each wear
cap 88 positioned adjacent a hammer pocket may be increased
by reversing the wear cap 88 to position the lesser worn
edge of the wear cap 88 adjacent the hammer pocket.
In the preferred embodiment illustrated, hammer
supports 86 are formed from mild or alloy steel. Wear caps
88 are preferably formed from cast manganese steel. As can
be appreciated, hammer supports 86 and wear caps 88 may
alternatively be formed from a variety of different
materials having various hardnesses depending upon the
particular materials being shredded and the anticipated
wear of the caps 88. Moreover, wear caps 88 may be omitted
in favor of each intermediate segment 50a-50m being formed
as a single unitary body made of a single or several
composite materials.
In conclusion, rotor 12 more effectively shreds
material in hammermills and shredders. In contrast to
conventional disk style rotors, rotor 12 provides full
cutting action along the axis of rotor 12 to improv~
material feeding and shredding efficiency. As compared to
-
CA 02216389 1997-09-24
conventional spider style rotors, rotor 12 provides full
cutting action along the axis of the rotor with fewer or
smaller gaps or openings about and along rotor axis X.
Because rotor 12 reduces the number or size of gaps along
and about rotor axis X, rotor 12 is less susceptible to
wear, material clogging and impact damage. In the
preferred embodiment illustrated, rotor 12 has a rotor body
69 that is substantially imperforate but for concavities 64
which contain hammers 13. At the same time, rotor 12
provides a rotor that is statically and dynamically
balanced.
Although the present invention has been described with
reference to preferred embodiments, workers skilled in the
art will recognize that changes may be made in form and
detail without departing from the spirit and scope of the
invention.
