Abstrict An improved cone crusher for crushing rock and the like has a welded
metal hardfacing pattern made by welding beads of chromium carbide
or similar hardfacing material to selected portions of its crushing
surfaces. Tungsten carbide particles are introduced into the weld
puddle as the beads are deposited. Predetermined spacing is maintained
between adjacent beads to expose portions of the crushing surfaces.
The beads can be deposited in recessed grooves in the crushing surfaces
for increased lateral support. In the preferred embodiment, the
beads are welded in a concentric circular pattern on the mantle
and bowl liner of the cone crusher.
Claims I claim:
1. In a rock crusher having opposing metallic crushing surfaces,
the improvement comprising a hardfacing pattern of metallic beads
welded to recessed grooves in said crushing surfaces with spacing
maintained between adjacent beads to expose portions of said crushing
surfaces, wherein tungsten carbide particles are inserted into said
welded beads as they are deposited on said crushing surfaces.
2. The rock crusher of claim 1 wherein said welded beads further
comprise chromium carbide.
3. The rock crusher of claim 3 wherein said grooves have a depth
of approximately 1/4 to 1/2 inches.
4. The rock crusher of claim 4 wherein said welded beads have
a thickness of approximately 3/8 to 3/4 inches.
5. The rock crusher of claim 1 wherein said welded beads have
a width of approximately 3/8 to 3/4 inches.
6. The rock crusher of claim 1 wherein said spacing between adjacent
beads is approximately 3/16 inches.
7. In a cone crusher for crushing rock having a mantle with a generally
convex, annular crushing surface and a bowl liner with a generally
concave, annular crushing surface, the improvement comprising a
pattern of recessed grooves on selected portions of said crushing
surface of said mantle and bowl liner filled with welded metallic
beads with spacing maintained between adjacent beads to expose portions
of said crushing surfaces, wherein tungsten carbide particles are
inserted into said welded beads as they are deposited in said recessed
grooves.
8. The cone crusher of claim 7 wherein said welded beads further
comprise chromium carbide.
9. The cone crusher of claim 7 wherein said welded beads have
a width of approximately 3/8 to 3/4 inches.
10. The cone crusher of claim 7 wherein said grooves have a depth
of approximately 1/4 to 1/2 inches.
11. The cone crusher of claim 10 wherein said welded beads have
a thickness of approximately 3/8 to 3/4 inches.
12. The cone crusher of claim 7 wherein said spacing between adjacent
beads is approximately 3/16 inches.
13. In a cone crusher for crushing rock and the like, having a
mantle with a generally convex, annular crushing surface extending
radially outward about a first axis and a bowl liner with a generally
concave, annular crushing surface extending radially outward about
a second axis, the improvement comprising:
a concentric circular hardfacing pattern of metallic beads welded
to recessed grooves in said mantle crushing surface about said first
axis with spacing maintained between adjacent beads to expose portions
of said mantle crushing surface, wherein tungsten carbide particles
are inserted into said beads as said beads are deposited on said
mantle crushing surface; and
a concentric circular hardfacing pattern of metallic beads welded
to recessed grooves in said bowl liner crushing surface about said
second axis with spacing maintained between adjacent beads to expose
portions of said bowl liner crushing surface, wherein tungsten carbide
particles are inserted into said beads as said beads are deposited
on said bowl liner crushing surface.
14. The cone crusher of claim 13 wherein said welded beads further
comprise chromium carbide.
15. The cone crusher of claim 13 wherein said welded beads have
a width of approximately 3/8 to 3/4 inches.
16. The cone crusher of claim 13 wherein said grooves have a depth
of approximately 1/4 to 1/2 inches.
17. The cone crusher of claim 16 wherein said welded beads have
a thickness of approximately 3/8 to 3/4 inches.
18. The cone crusher of claim 13 wherein said spacing between
adjacent beads is approximately 3/16 inches.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of cone crushers
used for crushing rock, and other material. More specifically, the
present invention discloses a hardfacing pattern for cone crusher
surfaces in which a series of welded beads containing tungsten carbide
particles are welded to the crusher surfaces with spacing between
the beads.
2. Statement of the Problem
Cone crushers are typically used for crushing rock, ore, construction
materials, and the like and have a cross-section similar to that
shown in FIG. 1. The cone crusher 10 includes a mantle (or breaking
cone) 30 mounted on a shaft 50 and a bowl liner 20 within which
the mantle 30 is disposed. As shown in greater detail in FIG. 2
the mantle 30 has a generally convex annular or tapered conical
shape that extends radially outward from an axis that is off-vertical.
The upper surface of the mantle 30 functions as a crushing surface
during operation of the cone crusher, as depicted in FIG. 1. The
bowl liner 20 is normally mounted about a vertical axis and features
a substantially concave annular crusher surface as shown in FIG.
3.
A motor drives the shaft 50 and mantle 30 to gyrate relative to
the bowl liner 20. Rocks 40 or other material to be crushed are
introduced into the hopper formed by the upper portion of the bowl
liner 20. The rocks 40 fall into the space separating the mantle
30 from the bowl liner 20. The gyrating motion of the mantle 30
causes these rocks to be crushed between the mantle 30 and the bowl
liner 20.
The crushing surfaces of both the mantle 30 and bowl liner 20 are
made of a tough metallic material such as manganese steel. These
crushing surfaces are frequently covered with a thin, continuous
layer of a harder material (known as hardfacing) to enhance the
wear characteristics of the assembly. For example, a continuous
layer containing chromium carbide is sometimes applied to the crushing
surfaces. The hardfacing can be applied by welding overlapping beads
to form a substantially continuous layer over the manganese steel
crushing surfaces.
A number of cone crushers have been invented in the past, including
the following:
______________________________________ Inventor Pat. No. Issue
Date ______________________________________ Axhelm 3075067 Jan.
22 1963 Adam et al. 3583649 June 8 1971 Werginz 4168036 Sep.
18 1979 Arakawa 4976470 Dec. 11 1990 Saari 5115991 May 26
1992 Schwechten German OLS Nov. 19 1992 4116374 ______________________________________
Axhelm discloses an automatic welding apparatus for making a continuous
weld on the surface of a crusher roller. This results in a smooth
hard surface on the worn roller (col. 1 lines 31-34).
Adam et al. disclose a wear part for use in a crusher. The crushing
member is prestressed in compression sufficiently to overcome the
tension stresses normally produced by the crushing operation. This
prestressing may be accomplished by an annular band secured around
the outer circumference of the crushing member.
Werginz discloses a cone crusher having an improved frame structure,
an anti-spin mechanism, and an improved crusher setting indicator.
FIG. 1 of the Werginz patent indicates that the crushing surfaces
of the mantle 191 and the bowl liner 17 have a number of annular
lips or edges.
Arakawa discloses a cone crusher having a gyrating mantle and a
bowl liner above the mantle. The space between the mantle and bowl
liner is automatically adjusted by hydraulic pressure that moves
the bowl liner upward to accommodate load fluctuations and abnormal
overloads.
Saari discloses another example of a gyratory cone crusher. The
space separating the crushing surfaces can be adjusted by actuation
of hydraulic cylinders pivotally connected to both the main frame
and the bowl assembly.
Schwechten discloses a method for producing a wear-resistant surface
by applying a coating of a hard material. Fields of hard material
are obtained by filling the depressions formed by ridges of a buffer
material connected with the base material of the machine part. The
ridges of buffer material are formed by casting, machining, or welding.
The hard material can be applied by casting or welding. The drawings
suggest that the entire surface of the machine part is to be covered
by the ridges and hard material. The invention is intended for use
in roll mills, rock crushers, briquette and pellet presses, forging
equipment, and other similar equipment.
Tungsten carbide has long been known to have a hardness close to
that of diamond. Consequently, tungsten carbide has been used extensively
for cutting or grinding in situations requiring extreme resistance
to wear and abrasion. The following are a few examples:
______________________________________ Inventor Pat. No. Issue
Date ______________________________________ Brady et al. 4682987
July 28 1987 Hall 4694918 Sep. 22 1987 Beakley 4610320 Sep.
9 1986 Terrenzio 4513919 Apr. 30 1985 ______________________________________
Brady et al. disclose a method and composition for producing hard
surface carbide insert tools. A slurry coating containing hard nickel,
metal alloy powder, and a fluxing agent is fused to bond an abrasive
insert, such as tungsten carbide in a base metal matrix, to a cutting
tool.
Hall discloses a percussion rock bit with a plurality of diamond
tip inserts. The inserts have a cemented tungsten carbide body partially
embedded in the steel bit and at least two layers at the protruding
drilling portion of the insert. The outermost layer contains polycrystalline
diamond. The remaining layers are transition layers containing a
composite of diamond crystals and precemented tungsten carbide.
Beakley discloses a method for applying large tungsten carbide
particles to the surface of stabilizer blades used in the drilling
of oil, gas, geothermal and water wells. A soft, elastic metal powder
is first applied to the substrate surface, as shown in FIG. 2 of
the Beakley patent. Large tungsten carbide particles 20 that have
also been coated with the soft powder are placed on top of the layer
of soft powder, as shown in FIG. 3 of the patent. The tungsten carbide
particles 20 are covered with additional soft powder, which is then
fused to form a homogeneous mixture bonded to the substrate. A hard
matrix 30 is applied and fused over the mixture 14 below, as shown
in FIG. 5.
Terrenzio discloses a feed arrangement for a centrifugal rock crusher
having a circular housing and an impeller that rotates concentrically.
The impeller throws rock against an impact surface within the housing
to crush the rock. Terrenzio further discusses that the wear life
of the end surfaces 146 of the lip body 142 can be extended by imbedding
an insert made of a hard material, such as tungsten carbide, within
the end of the lip body 142 (column 9 lines 47-63).
3. Solution to the Problem. None of the prior art references uncovered
in the search show a cone crusher having a metal hardfacing pattern
made by welding staggered beads containing tungsten carbide particles
to the crushing surfaces with spacing between adjacent beads to
expose portions of the crushing surfaces. This is counter-intuitive
in that incomplete covering of the crushing surfaces would generally
be expected to reduce wear life. Instead, use of the invention in
the field has consistently demonstrated that wear life is doubled
or tripled over that of conventional cone crushers.
It is believed that the staggered beads in the present invention
serve to reduce high stress patterns that otherwise occur within
crushing surfaces having a continuous layer of hardfacing. These
high stress levels can cause propagation of cracks that destroy
the crushing surfaces. The welded beads in the present invention
do not form a continuous layer, and therefore help to resist crack
propagation through the crushing surfaces.
Another factor that may contribute to increased wear life in the
present invention relates to the work hardening characteristics
of the manganese steel commonly used to form the crushing surfaces.
Manganese steel gradually hardens as it is subject to repeated deformation.
However, in a conventional cone crusher, the manganese steel on
the exposed top layer of the crushing surfaces may be worn away
by the rock before significant work hardening can occur. Similarly,
in a conventional cone crusher with a continuous layer of hardfacing
above the manganese steel, the hardfacing is harder than manganese
steel and tends to protect the underlying manganese steel from deformation
and work hardening until the hardfacing has been worn away. In contrast,
the spacing between adjacent welded beads in the present invention
subjects the manganese steel substrate to significantly greater
deformation during the crushing operation. This gives the manganese
steel extensive time to work harden before the hardfacing pattern
wears away. The welded beads in the present invention also serve
to better grip the rock to produce a more uniform end product.
SUMMARY OF THE INVENTION
This invention provides an improved cone crusher for crushing rock
and the like having a welded metal hardfacing pattern made by welding
beads of chromium carbide or similar hardfacing material to selected
portions of its crushing surfaces. Tungsten carbide particles are
introduced into the weld puddle as the beads are deposited. The
beads are staggered to maintain spacing between adjacent beads and
thereby expose portions of the crushing surfaces. The beads can
be deposited in recessed grooves in the crushing surfaces for increased
lateral support. In the preferred embodiment, the beads are welded
in a concentric circular pattern on the mantle and bowl liner of
the cone crusher.
A primary object of the present invention is to provide a means
for greatly extending the wear life of the crushing surfaces in
a cone crusher.
Another object of the present invention is to provide a means for
allowing the crushing surfaces to better grip the rocks and thereby
produce a more uniform end product.
These and other advantages, features, and objects of the present
invention will be more readily understood in view of the following
detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more readily understood in conjunction
with the accompanying drawings, in which:
FIG. 1 is a side cross-sectional view of a cone crusher with crushing
surfaces that incorporate the present invention.
FIG. 2 is a perspective view of the mantle of the cone crusher
shown in FIG. 1.
FIG. 3 is a perspective view of the bowl liner of the cone crusher
shown in FIG. 1.
FIG. 4 is a cross-sectional view of a portion of the surface of
the mantle with small welded beads.
FIG. 5 is a cross-sectional view of a portion of the surface of
the mantle with heavier welded beads for coarse crushing.
FIG. 6 is a cross-sectional view of a portion of the surface of
the mantle with wider welded beads for crushing finer materials
FIG. 7 is a side view of the mantle in a second embodiment of the
present invention in which the welded beads are deposited into recessed
grooves in the mantle and tungsten carbide particles are introduced
into the weld puddle as the beads are deposited.
FIG. 8 is a cross-sectional view of the mantle corresponding to
FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 provides a cross-sectional view of a cone crusher 10 embodying
the present invention. As previously discussed, the cone crusher
includes a bowl liner 20 and mantle 30. The mantle 30 is mounted
on and supported by a shaft 50 that gyrates about an axis at a predetermined
angle with respect to the vertical axis of the bowl liner. The crushing
surfaces of the mantle 30 and bowl liner 20 are made of conventional
manganese steel as previously discussed.
The crushing surfaces of the mantle 30 and bowl liner 20 are first
sandblasted to ensure clean surfaces for welding. A pattern of welded
beads 22 and 32 is then applied to the crushing surfaces. The beads
are applied by open arc welding in the preferred embodiment, although
other welding techniques could be used instead. A space 33 is intentionally
left between adjacent beads 32 on the mantle 30 so that portions
of the underlying manganese steel crushing surface remain exposed.
This is shown most clearly in FIGS. 4-6. Similarly, a space 23 is
also left between adjacent beads 22 on the bowl liner 20 to exposed
portions of the underlying manganese steel crushing surface.
Virtually any pattern of welded beads can be applied to the mantle
30 and bowl liner 20. In the preferred embodiment, a concentric
circular pattern of beads is welded to each crushing surface. As
shown in FIGS. 1 and 3 the crushing surface of bowl liner 20 has
a generally concave annular shape extending radially outward from
the vertical axis. Given this configuration, the welded beads 22
are applied as a series of concentric rings centered about the vertical
axis. Similarly, the mantle 30 has a generally convex annular crushing
surface extending radially outward from an axis of symmetry that
is off-vertical. Here again, the welded beads 32 am applied as a
series of concentric rings centered about this axis of symmetry.
Concentric circular patterns of this type tend to better grip the
rock as it descends from the hopper into the space between the crushing
surfaces of the mantle 30 and the bowl liner 20. This gripping action
retards rocks from falling too quickly through the crusher, and
thereby helps ensure thorough crushing of the rock and a more uniform
end product.
The beads can be manually applied by an experienced welder, or
by means of a welding machine that automatically applies each circular
bead and then indexes radially inward (or outward) by a predetermined
increment to apply the next circular bead in the pattern. Alternatively,
the welded beads can have the form of spirals, lines, or other shapes.
The beads should be harder than the underlying substrate (e.g.,
manganese steel) of the crushing surfaces. In the preferred embodiment,
the beads are created with a Stoody 100HC welding rod (Stoody Company,
Bowling Green, Ky.) having a composition of approximately 4.3% carbon,
1.5% manganese, 1.5% silicon, 25% chromium, 1% molybdenum, and the
balance iron. This welding rod forms a bead containing a substantial
proportion of chromium carbide. It should be expressly understood
that other welding rod formulations could be substituted. In addition,
any of a wide variety of equivalent hardfacing materials known in
the industry could be employed that are harder than manganese steel.
The previous discussion has assumed that welded beads are applied
to both the mantle 30 and bowl liner 20. It should be understood
that the cone crusher will function satisfactorily even if the beads
are applied to only one of the crushing surfaces, although wear
life might not be as long. It is also possible to apply the welded
beads only to selected portions of each crushing surface.
FIGS. 4 through 6 show examples of three different sizes of welded
beads 32 that can be applied to the crushing surfaces. The smallest
bead size shown in FIG. 4 has a width of approximately 3/8 inches,
a height of approximately 3/16 inches, and a spacing 33 between
adjacent beads of approximately 3/16 inches. These dimensions have
been found suitable for all-purpose rock crushing, but especially
for material ranging from 3/8 to 3/4 inch material.
The heavier beads 32 shown in FIG. 5 are intended primarily for
coarser crushing (i.e., material sizes of 7/8 inches and larger).
Here, the beads have a width of approximately 5/8 inches, a height
of approximately 3/16 inches, and a spacing 33 between adjacent
beads of approximately 3/16 inches.
Finally, the wider beads 32 shown in FIG. 6 are used primarily
for fine crushing for material sizes of 1/4 inch and less. The beads
32 have a width of approximately 7/8 inches, a height of approximately
3/16 inches, and a spacing 33 between adjacent beads of approximately
3/16 inches.
The bead can be formed in a single pass, or alternatively by a
plurality of overlapping beads deposited in several passes. Multiple
passes are especially helpful in creating wider beads as shown in
FIG. 6. It is also possible to create a bead having bands of dissimilar
materials by means of multiple passes. For example, two side ridges
for each bead can be made by using a Stoody 100HC welding rod. The
region between the two side ridges is then filled in by using a
Stoody 145 welding rod to create a single bead. Spacing is maintained
between adjacent beads, as previously discussed.
A welded metal hardfacing pattern can also be applied to the crushing
surfaces of a rock crusher using the alternative embodiment of the
present invention, as shown in the side view of a mantle 30 illustrated
in FIG. 7. A corresponding cross-sectional view is provided in FIG.
8. A number of grooves 35 are first ground or cut into the crushing
surface of the mantle 30. The grooves 35 are then filled with a
welded metallic bead as shown in the right-hand portion of FIG.
7. For example, a conventional arc welding process can be used to
deposit a welded bead containing chromium carbide or other hardfacing
materials into the grooves 35. Particles of tungsten carbide 70
are introduced into the weld puddle through a tubular feeder 75
as the bead is deposited in each groove 35 by the electrode feed
system 65.
Tungsten carbide has a hardness approaching that of diamond, but
it is very brittle. The grooves 35 in the crushing surfaces contain
the tungsten carbide particles 70 and chromium carbide within the
matrix of the welded bead to provide lateral support. This enhances
the ability of the tungsten carbide particles in the welded bead
to withstand the impact of crushing and yet gives outstanding wear
performance.
FIGS. 7 and 8 also show one means for depositing the welded beads
and introducing tungsten carbide into the weld puddle. A number
of grooves 35 are first ground into the crushing surface of the
mantle 30 by conventional means. The grooves 35 typically form either
a concentric circular pattern or a spiral pattern about the axis
of the mantle 30 although other patterns could be used. In the
preferred embodiment, the grooves have a width of approximately
3/8 to 3/4 inches and a depth of approximately 1/4 to 1/2 inches.
The spacing 33 between adjacent grooves is approximately 3/16 inches,
as previously discussed. A fixture is then used to rotate the mantle
30 about its axis, while the electrode feed system 65 and the feeder
tube 75 for the tungsten carbide particles 70 remain essentially
stationary. The electrode feed system 65 gradually advances the
welding rod, which contains a high percentage of chromium and carbon,
as before, to form a bead containing a substantial proportion of
chromium carbide. The electrical arc between the welding rod and
the crushing surface causes the bead to be deposited into the groove
35 as it passes beneath the tip of the welding rod. Tungsten carbide
particles are introduced through the feeder tube 75 into the weld
puddle while it remains molten. The final welded bead 32 overfills
the groove 35 to create a generally circular or oval cross-sectional
shape extending above the surface of the mantle, as shown in FIG.
7. The width of each welded bead is roughly equal to the width of
the groove 35 (i.e., approximately 3/8 to 3/4 inches). The depth
or thickness of each bead is approximately 3/8 to 3/4 inches, which
is usually fixed as a function of the width and depth of the groove.
The welded bead can be deposited in a single rotation of the fixture,
or by an accumulation of layers over multiple rotations if desired.
Accumulation over multiple rotations may be advantageous in helping
to distribute the tungsten carbide particles more evenly throughout
the bead.
If the grooves 35 form concentric circles, the electrode feed system
65 and the tungsten carbide feeder tube 75 remain stationary as
each groove is filled over one or more rotations of the fixture,
and then index laterally to the next groove to repeat the procedure.
If the groove 35 forms a spiral, the electrode feed system 65 and
the tungsten feeder tube 75 slowly move laterally to track the spiral
shape of the groove as the mantle rotates.
FIG. 7 and 8 show the welded bead being deposited on the crushing
surface of the mantle 30. It should be expressly understood that
the present invention can also be readily applied to the crushing
surface on the bowl liner 20 of a cone crusher. It could also be
readily adapted to virtually any other type of rock crusher.
The above disclosure sets forth a number of embodiments of the
present invention. Other arrangements or embodiments, not precisely
set forth, could be practiced under the teachings of the present
invention and as set forth in the following claims.
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