Abstrict A distributor plate adapted to be releasably mounted on a horizontal
lower disc of a rotor of a vertical shaft impact crusher. The rotor
has an opening for the intake of material to be crushed and at least
one outflow opening for material leaving the rotor. The distributor
plate is an equilateral polygon as seen from above.
Claims 1. A distributor plate adapted to be releasably mounted on a horizontal
lower disc of a rotor of a vertical shaft impact crusher, said rotor
having an opening for the intake of material to be crushed and at
least one outflow opening for material leaving the rotor, wherein
a shape of the distributor plate is an equilateral polygon as seen
from above.
2. A distributor plate according to claim 1 wherein the shape
of the distributor plate is selected from the group consisting of
triangular, square, hexagonal, octagonal and nonagonal shapes.
3. A distributor plate according to claim 1 wherein the number
of sides of the polygon being chosen is selected such that the number
of sides is 1 2 or 3 times the number of outflow openings of the
rotor to which the distributor plate is to be mounted.
4. A distributor plate according to claim 3 wherein the number
of sides is 2 times the number of outflow openings of the rotor.
5. A distributor plate according to claim 1 wherein at least one
straight side edge of the distributor plate is adapted to be parallel
to an outflow direction of material leaving the rotor and to be
parallel and adjacent to a face of a lower wear plate protecting
the lower disc from wear.
6. A distributor plate according to claim 1 wherein the distributor
plate at the centre of its lower face has a recess adapted to make
the distributor plate horizontally turnable around a vertical shaft
mounted on the lower disc, such that the position of the distributor
plate in relation to the lower disc may be adjusted before mounting
the distributor plate.
7. A distributor plate according to claim 6 wherein the recess
extends only through a part of the thickness of the distributor
plate, the upper face of the distributor plate thus being unaffected
by said recess.
8. A distributor plate according to claim 6 wherein the distributor
plate has a lower surface which is adapted to be located at a higher
level than the upper surface of lower wear plates protecting the
lower disc of the rotor, such that the distributor plate may be
adjusted without removing the lower wear plates.
9. A distributor plate according to claim 1 wherein the upper
face of the distributor plate comprises an unbroken layer of a hard
metal.
10. A distributor plate according to claim 1 wherein the distributor
plate comprises mounting means located at a vertical side edge of
the distributor plate and adapted for the mounting of a vertical
support fixing the distributor plate to the lower disc of the rotor.
11. A rotor for a vertical shaft impact crusher, the rotor having
an opening for the intake of material to be crushed, at least one
outflow opening for material leaving the rotor, and at least one
lower wear plate and a distributor plate releasably mounted on a
horizontal lower disc of the rotor, wherein the distributor plate
is has a shape defined by an equilateral polygon as seen from above,
at least one straight side edge of the distributor plate being parallel
to an outflow direction of material leaving the rotor and being
parallel to and adjacent to a face of the lower wear plate.
12. A distributor plate according to claim 9 wherein the upper
face of the distributor plate comprises an unbroken layer of tungsten
carbide.
Description TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a distributor plate adapted
to be releasably mounted on a horizontal lower disc of a rotor of
a vertical shaft impact crusher, said rotor having an opening for
the intake of material to be crushed and at least one outflow opening
for material leaving the rotor.
[0002] The present invention also relates to a rotor for a vertical
shaft impact crusher, the rotor having an opening for the intake
of material to be crushed, at least one outflow opening for material
leaving the rotor, and at least one lower wear plate and a distributor
plate releasably mounted on a horizontal lower disc of the rotor.
BACKGROUND ART
[0003] Vertical shaft impact crushers (VSI-crushers) are used in
many applications for crushing hard material like rocks, ore etc.
U.S. Pat. No. 3154259 describes a VSI-crusher comprising a housing
and a horizontal rotor located inside the housing. Material that
is to be crushed is fed into the rotor via an opening in the top
thereof. With the aid of centrifugal force the rotating rotor ejects
the material against the wall of the housing. On impact with the
wall the material is crushed to a desired size. The housing wall
could be provided with anvils or have a bed of retained material
against which the accelerated material is crushed.
[0004] The rotor of a VSI-crusher usually has a horizontal upper
disc and a horizontal lower disc. The upper and lower discs are
connected with a vertical rotor wall. The upper disc has an aperture
for feeding material into the rotor. The material lands on the lower
disc and is then thrown out of the rotor via openings in the rotor
wall.
[0005] The material exerts an impact force and wear on the lower
disc. To ensure a long life of the lower disc it is usually provided
with a distributor plate. The distributor plate, which is located
at the centre of the lower disc, is made from a material that is
resistant to impact and wear.
[0006] In U.S. Pat. No. 3767127 to Wood a deflection disc assembly
is described. The deflection disc has an outer ring and a core member.
A central stud passing through the core member and threadedly engaged
to the rotor shaft holds the deflection disc in position in the
rotor.
[0007] U.S. Pat. No. 4690341 to Hise describes a flat centre
wear plate which is fixed to the rotor shaft by a bolt.
[0008] WO 01/30501 describes a distributor comprising a first part
having an inclined surface and a second part with a flat surface.
A bolt holds the first and second parts fixed to a rotor shaft.
[0009] The distributor plates described above do not have a very
long life and cause a rather long down time when they need to be
replaced. To make it possible for a person working with the rotor
to replace the distributor plate it is often necessary to dismantle
the top of the rotor.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a distributor
plate which has a longer life and which decreases the down time
required for maintenance of the rotor.
[0011] This object is achieved with a distributor plate according
to the preamble and characterised in that the distributor plate
is an equilateral polygon as seen from above.
[0012] An advantage with this distributor plate is that its life
is greatly increased. The polygonal shape provides straight side
edges which decrease the wear, particularly at the periphery of
the distributor plate. A possible explanation is that much of the
wear at the periphery of the distributor plate may be caused by
dust loaded air streams circulating inside the rotor. Those air
streams may be hindered by the straight side edges thus reducing
the wear. A polygon has several straight side edges and would thus
be able to efficiently hinder any dust loaded air streams.
[0013] Preferably the distributor plate has a shape chosen among
triangular, square, hexagonal, octagonal and nonagonal shapes. An
advantage with these particular shapes is that they are particularly
efficient in hindering dust loaded air streams from circulating
inside the rotor. In particular the hexagonal, octagonal and nonagonal
shapes are also very robust to large pieces of material impacting
the distributor plate. Still more preferably said polygon is an
equilateral polygon, the number of sides of the polygon being chosen
such that the number of sides is 1 2 or 3 times the number of outflow
openings of the rotor to which the distributor plate is to be mounted.
An equilateral polygon makes it easier to balance the rotor. The
distributor plate should have at least one side edge corresponding
to each outflow opening of the rotor. If the number of sides of
the distributor plate is 2 or 3 times the number of outflow openings
it is possible to turn the distributor plate after some time in
operation such that the sides being adjacent to the outflow openings
is changed. Thus the life of the distributor plate is prolonged.
Preferably the number of sides is 2 times the number of outflow
openings of the rotor. This design has proven to give both a long
life, possibly due to the fact that such a number of sides are especially
efficient in hindering the rotating air streams inside the rotor,
and the possibility to turn the distributor plate after some time
of operation to further increase its life.
[0014] Preferably at least one straight side edge of the distributor
plate is adapted to be parallel to an outflow direction of material
leaving the rotor and to be parallel and adjacent to a face of a
lower wear plate protecting the lower disc from wear. This design
has proven to give a long life for both the distributor plate, the
lower wear plate and the lower disc due to the fact that swirling
of dust loaded air streams on the lower wear plate and on the lower
disc is efficiently prevented by the distributor plate when located
in this relation to the lower wear plate and to the direction of
material leaving the rotor. It is also easy to make the distributor
plate fit with a horizontal wear plate extending from a position
close to the centre of the rotor and towards the outflow opening.
[0015] According to a preferred embodiment the distributor plate
at the centre of its lower face has a recess adapted to make the
distributor plate horizontally turnable around a vertical shaft
mounted on the lower disc, such that the position of the distributor
plate in relation to the lower disc may be adjusted before mounting
the distributor plate. The recess makes it easy to centre the distributor
plate on the rotor. After centring the distributor plate it may
be turned around the shaft until the correct position of the edge/-s
is obtained, the distributor plate still being safely centred. It
also becomes easy to turn the distributor plate to some degree after
it has become worn. This makes it possible to quickly turn the distributor
plate to a new position without having to dismount the rotor. Thus
maintenance stops become quick and efficient. Still more preferably
the recess extends only through a part of the thickness of the distributor
plate, the upper face of the distributor plate thus being unaffected
by said recess. An advantage with this design is that the upper
surface of the distributor plate obtains a much better impact and
wear resistance since it is unbroken. The central part of the distributor
plate is exposed both to heavy impact wear and possibly also to
wear caused by dust loaded air streams circulating inside the rotor.
The risk of rocks breaking a central bolt and the risk of an excessive
wear of a central bolt or of a cap protecting a central bolt is
thus avoided with the design of the present invention. Also it becomes
easier to manufacture the distributor plate with the unbroken upper
surface, in particular if the upper surface is to be provided with
a layer of extra resistant material.
[0016] Preferably the upper face of the distributor plate comprises
an unbroken layer of a hard metal, such as tungsten carbide. Such
a layer of hard metal will substantially prolong the life of the
distributor plate and thus decrease maintenance costs.
[0017] According to a preferred embodiment the distributor plate
comprises mounting means located at a vertical side edge of the
distributor plate and adapted for the mounting of a vertical support
fixing the distributor plate to the lower disc of the rotor. An
advantage with such mounting means is that they do not interact
with the upper surface of the distributor plate. Another advantage
is that the distributor plate will provide some protection for the
mounting means located below the actual material flow. The mounting
means may also be fitted and removed without having to lift the
entire distributor plate.
[0018] It is another object of the present invention to provide
a rotor which require less down time for maintenance.
[0019] This object is achieved with a rotor according to the preamble
and characterised in that the distributor plate is an equilateral
polygon as seen from above, at least one straight side edge of the
distributor plate being parallel to an outflow direction of material
leaving the rotor and being parallel to and adjacent to a face of
the lower wear plate.
[0020] An advantage of this rotor is that the polygonal shape of
the distributor plate decreases the wear inside the rotor and thus
maintenance stops may be made less frequently. The straight side
edge of the distributor plate fit with the adjacent and parallel
face of the wear plate to hinder any wear at the underlying lower
disc of the rotor.
[0021] These and other aspects of the invention will be apparent
from and elucidated with reference to the embodiments described
hereafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will hereafter be described in more detail
and with reference to the appended drawings.
[0023] FIG. 1 is three-dimensional section view and shows a rotor
for a VSI-crusher
[0024] FIG. 2 is a three-dimensional view and shows the rotor of
FIG. 1 with the upper disc removed.
[0025] FIG. 3 shows the view of FIG. 2 as seen from above in a
two dimensional perspective.
[0026] FIG. 4 is an enlargement of the central portion of FIG.
3 and shows a distributor plate.
[0027] FIG. 5 is a sectional view along the line V-V of FIG. 4.
[0028] FIG. 6 is a three-dimensional view of the distributor plate.
[0029] FIG. 7 is a three-dimensional view as seen along the arrow
VII of FIG. 4.
[0030] FIG. 8 is a three-dimensional view of a distributor plate
according to a second embodiment of the invention.
[0031] FIG. 9 is a three-dimensional view and shows an alternative
way of releasably fixing the distributor plate.
[0032] FIG. 10 is an enlargement of the area X shown in FIG. 9.
[0033] FIG. 11 shows the distributor plate before being secured
to the mounting plate.
[0034] FIG. 12 shows a locking member for securing the distributor
plate to the mounting plate.
[0035] FIG. 13 is a three-dimensional view of a distributor plate
according to a third embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0036] FIG. 1 shows a rotor 1 for use in a VSI-crusher. The rotor
1 has a roof in the form of an upper disc 2 having a top wear plate
3 and a floor in the form of a lower disc 4. The lower disc 4 has
a hub 6 which is welded to the disc 4. The hub 6 is to be connected
to a shaft (not shown) for rotating the rotor 1 inside the housing
of a VSI-crusher.
[0037] The upper disc 2 has a central opening 8 through which material
to be crushed can be fed into the rotor 1. The upper disc 2 is protected
from wear by upper wear plates 10 and 12. The upper disc 2 is protected
from rocks impacting the rotor 1 from above by the top wear plate
3. As is better shown in FIG. 2 the lower disc 4 is protected from
wear by three lower wear plates 14 16 and 18.
[0038] The upper and lower discs 2 4 are separated by and held
together by a vertical rotor wall which is separated into three
wall segments 20 22 and 24. The gaps between the wall segments
20 22 24 define outflow openings 26 28 30 through which material
may be ejected against a housing wall.
[0039] At each outflow opening 26 28 30 the respective wall segment
20 22 24 is protected from wear by three wear tips 32 34 36
located at the trailing edge of the respective wall segment 20
22 24.
[0040] A distributor plate 38 is fastened to the centre of the
lower disc 4. The distributor plate 38 distributes the material
that is fed via the opening 8 in the upper disc 2 and protects the
lower disc 4 from wear and impact damages caused by the material
fed via the opening 8.
[0041] During operation of the rotor 1 a bed 40 of material is
built up inside the rotor 1 against each of the three wall segments
20 22 24. In FIG. 3 only the bed 40 located adjacent to the wall
segment 20 is shown. The bed 40 which consists of material that
has been fed to the rotor 1 and then has been trapped inside it,
extends from a rear support plate 42 to the wear tips 32 34 36.
The bed 40 protects the wall segment 20 and the wear tips 32 34
36 from wear and provides a proper direction to the ejected material.
The dashed arrow A describes a typical passage of a piece of rock
fed to the rotor 1 via the central opening 8 and ejected via the
outflow opening 26. The arrow R indicates the rotational direction
of the rotor 1 during operation of the VSI-crusher.
[0042] Each wall segment 20 22 24 is provided with a cavity wear
plate 44 46 48 each consisting of three cavity wear plate portions.
The cavity wear plates 44 46 48 protects the rotor 1 and in particular
the wear tips 32 34 36 from material rebounding from the housing
wall and from ejected material and airborne fine dust spinning around
the rotor 1.
[0043] In FIG. 4 the regularly hexagonal shape of the distributor
plate 38 is shown in greater detail. The distributor plate 38 has
six equilateral, vertical side edges 50 52 54 56 58 60. The
side edge 50 is substantially parallel to the outflow direction
B of the material leaving the rotor 1 via the outflow opening 26.
The side edge 50 is also parallel and adjacent with the face 62
of the wear plate 14. In a similar way the side edge 58 is adjacent
to the face 64 of the wear plate 16 and the side edge 54 is adjacent
to the face 66 of the wear plate 18. The distributor plate 38 has
a central flat area 68 from which a sloped surface 70 of the distributor
plate 38 extends towards the side edges 50 52 54 56 58 and 60.
[0044] The distributor plate 38 is removably fixed to the lower
disc 4 with the help of three vertical supports 72 74 76 fitted
to the side edges 52 56 60 that are not adjacent to a face of
a wear plate. Thus the vertical supports 72 74 76 are located
at some distance from the typical rock passage indicated with the
arrow A.
[0045] As is shown in FIG. 5 the distributor plate 38 rests on
a mounting plate 78. The mounting plate 78 has the same hexagonal
shape as the distributor plate 38 as seen from above. The mounting
plate 78 is bolted to the hub 6 and thus to the lower disc 4. A
vertically mounted central bolt 80 extending through the mounting
plate 78 is bolted at the centre of the hub 6. The distributor plate
38 has a central cylindrical recess 82 at its lower face 84. The
diameter and depth of the recess 82 is adapted to house the circular
top of the bolt 80 such that the bolt 80 centres the distributor
plate 38 on the lower disc 4. The lower face 84 of the distributor
plate 38 may slide on the upper surface of the mounting plate 78
when a locking member 206 according to an alternative embodiment
of a vertical support described below has been removed. The lower
surface 84 of the distributor plate 38 is located at a higher level
than the upper surfaces of the wear plates 14 16 18. Thus it is
possible to turn the distributor plate 38 on the mounting plate
78 without removing the wear plates 14 16 18.
[0046] The flat area 68 and the sloped surface 70 together form
an unbroken upper surface 86 of the distributor plate 38 as indicated
in FIG. 6. The distributor plate 38 shown in FIG. 6 is made entirely
from white iron. Each vertical side edge 50 52 54 56 58. 60
has a mounting means in the form a of a hole 88 as shown in FIG.
6. The hole 88 may be provided with an inner thread to receive a
bolt 90 forming part of the support 72 74 and 76 respectively,
as seen in FIG. 7. As is shown in FIG. 7 the supports 72 74 76
are fitted in slots in the lower disc 4 and bolted to the distributor
plate 38 with the help of the bolts 90 thus holding the distributor
plate 38 in place.
[0047] The mounting of the distributor plate 38 is performed by
lowering it such that the recess 82 engages the top of the bolt
80. The distributor plate 38 is then turned in the horizontal plane
until the side edges 50 54 and 58 have the proper position in relation
to the wear plates 14 16 18. The supports 72 74 76 are mounted
to the distributor plate 38 such that it becomes fixed to the lower
disc 4.
[0048] After some time of operation of the rotor 1 the distributor
plate 38 has been subjected to some wear. The wear pattern often
has a certain relationship with the outflow openings, such that
the maximum wear often occurs at the side edges 50 54 58 being
adjacent to a horizontal wear plate. The supports 72 74 76 are
dismounted. The distributor plate 38 is now turned horizontally,
thus sliding on the upper surface of the mounting plate 78 until
the side edge 52 is adjacent to the face 62 of the wear plate 14
the side edge 56 being adjacent to the face 66 of the wear plate
18 and so on. The supports 72 74 76 are mounted again and the
rotor 1 is ready for operation. Thus it is possible to prolong the
life of the distributor plate 38 by simply turning it 60.degree.
in the horizontal plane after some time of operation. At the turning
sequence the distributor plate 38 need not be lifted, since it simple
slides on the mounting plate 78. The turning thus becomes very quick
and easy to perform.
[0049] In FIG. 8 another embodiment of the invention is shown.
The main difference compared to the distributor plate 38 is that
this embodiment is a distributor plate 138 in the form of an equilateral
triangle. The distributor plate 138 has a central flat area 168
from which a sloped surface 170 extends towards the three vertical
side edges 150 152 154. Each of the three vertical side edges
150 152 154 is adapted to be located adjacent to a face of a wear
plate. The distributor plate 138 is thus adapted for mounting at
a rotor having three outflow openings.
[0050] In FIG. 9 to 12 an alternative embodiment of the fixing
of the distributor plate 38 is shown. The mounting plate 78 is provided
with a pair of lugs 200 202 and a round mounting hole 204 as is
better shown in FIG. 11. A vertical support in the form of a locking
member 206 shown in FIG. 12 is provided with an upper pin 208
and a lower pin 210. The upper pin 208 fits into the hole 88 which
need not be threaded, of the distributor plate 38 and the lower
pin 210 fits into the mounting hole 204 of the mounting plate 78.
A spring dowel pin 212 is inserted via holes 214 216 in the lugs
200 202 to lock the locking member 206 in its proper position.
The locking member 206 thus fixes the distributor plate 38 to the
mounting plate 78. The locking member 206 is easily mounted by just
inserting its pins 208 210 into the hole 88 and the mounting hole
204 respectively followed by insertion of the spring dowel pin 212
such that it locks the locking member 206. The above described embodiment
provides for very quick mounting or turning of the distributor plate
38. Preferably pairs of lugs 200 202 are located at those sides
of the mounting plate 78 that are located at some distance from
a rock passage, such as the rock passage indicated with the arrow
A in FIG. 3. Thus the wear on the locking member 206 is minimized.
As indicated in FIG. 9 and FIG. 10 the upper part of the locking
member 206 is located below the upper surface 86 of the distributor
plate 38. Thus the feed material flowing over the upper surface
86 of the distributor plate 38 will flow over the locking member
206 without causing any substantial wear to it.
[0051] FIG. 13 shows a third embodiment of the invention. A hexagonal
distributor plate 338 shown in FIG. 13 has vertical side edges 350
352 354 and holes 388 that are similar to the vertical side edges
50 52 54 and holes 88 respectively of the distributor plate 38
described above. The upper surface 386 of the distributor plate
338 is flat. The distributor plate 338 comprises a base layer 340
made from a flat sheet of a hard steel. A top layer 342 of a hard
metal, such as tungsten carbide, has been coated on the flat upper
surface of the base layer 340. The distributor plate 338 having
the top layer 342 made of tungsten carbide has very good resistance
to wear and impact and will have a very long life. The flat upper
surface of the base layer 340 makes the tungsten carbide layer 342
easy to apply to the base layer 340. The fact that the upper surface
386 of the tungsten layer 342 will be flat as well also contributes
to making the application of the tungsten layer 342 simple. The
distributor plate 338 has a recess (not shown in FIG. 13) which
is similar to the recess 82 of the distributor plate 38. The fact
that no bolts or holes extend through the upper surface 386 avoids
the formation of any weak spots in the tungsten layer 342 thus further
improving its resistance to wear and impact.
[0052] It will be appreciated that numerous modifications of the
embodiments described above are possible within the scope of the
appended claims.
[0053] The number of edges and thus the polygonal shape of the
distributor plate may be varied to fit the rotor in question. For
a rotor with tree outflow openings a distributor with triangular
or hexagonal shape is preferably used. A nonagonal shape is also
possible. For at rotor with four outflow openings a distributor
having square or octagonal shape is preferably used. A dodecagonal
shape is also possible. A distributor plate having a number of side
edges being two times the number of outflow openings is preferable
since the distributor may be turned once for prolonged life. Triangular,
square, hexagonal, octagonal, nonagonal and dodecagonal shapes all
have the advantage of having only outwardly directed corners. This
avoids the swirling of dust loaded air and the subsequent wear that
may result from any inwardly directed corners. Further the hexagonal,
octagonal and nonagonal shapes have corners with obtuse angles.
Obtuse angles have the advantage of providing a distributor plate
which is less sensitive to impacting rocks, which may more easily
break a corner being right-angled or having an acute angle.
[0054] The lower surface 84 of the distributor plate 38 may, as
described above with reference to FIG. 5 be located above the upper
surfaces of the lower wear plates 14 16 18. For a rotor with a
very low vertical height it may however be necessary, for reasons
of maintaining the capacity for material passing through such a
rotor, to locate the distributor plate 38 such that its lower surface
84 rests directly on the lower disc 4 of the rotor. In such a case
the distributor plate 38 would need to be lifted somewhat such that
its lower surface 84 comes above the upper surfaces of the wear
plates 14 16 18 before the distributor plate 38 could be turned. |