Abstrict A gyratory crusher having a frame (1) and in the frame an eccentric
shaft (3) rotatable around a vertical shaft in the frame, with a
vertical inclined hole in it. A main shaft (4) is supported by bearings
in the hold of the eccentric shaft, a supporting cone (5) being
attached to the upper end of said main shaft (4). Around the main
shaft, below the supporting cone (5) there is a sealing cover (10)
covering the eccentric shaft. The upper edge (12) of the sealing
cover (10) is sealed against the main shaft (4) by means of a sealing
member (13), the outer edge of which has been fitted in an annular
groove (17) on the inner edge (12) of the sealing cover (10). The
face-to-face arranged upper and lower surfaces so the part (13")
of the sealing member (13) in the groove and the groove (17) of
the sealing cover (10) are inclined so that their outer edges are
higher up than their inner edges.
Claims We claim:
1. A gyratory crusher having
a frame;
an eccentric shaft rotatable around a vertical axis in the frame,
with a vertical inclined hole therein;
a main shaft supported by bearings in the hole of the eccentric
shaft, said main shaft comprising an upper end extending above the
eccentric shaft, and a supporting cone attached and supported thereto,
and
arranged around the main shaft, below the supporting cone, a sealing
cover covering the eccentric shaft, said sealing cover having an
inner edge, and an outer edge fastened tightly to the frame,
whereby the sealing cover is sealed against the main shaft with
a sealing member so that contact surfaces between the sealing cover
and the sealing member are formed in an annular groove and a part
fitted in the groove, said groove having the shape of the part fitted
in the groove, but being sideways wider than the portion of said
part fitted in said groove,
wherein the contact surfaces of both said groove and the part fitted
in said groove are inclined in such a way that radially outer edges
of said groove and the part are higher than radially inner edges
of said groove and the part.
2. A gyratory crusher in accordance with claim 1 wherein the groove
is arranged on the inner edge of the sealing cover, and the part
is a part of the sealing member.
3. A gyratory crusher in accordance with claim 2 wherein the face
to face arranged upper and lower surfaces of the groove and the
part define annular, partial surfaces of a sphere, a center of the
sphere being a center of oscillating movement of the main shaft
at the upper end of the main shaft.
4. A gyratory crusher in accordance with claim 2 wherein the sealing
member includes a flangelike part and a sleevelike part within it.
5. A gyratory crusher in accordance with claim 2 wherein the inner
edge of the sealing cover is sealed against the main shaft via a
protective sleeve fitted against the main shaft.
6. A gyratory crusher in accordance with claim 1 wherein the groove
is arranged between the sealing cover and a fixing ring on top of
it, and the part is a part of the sealing member.
7. A gyratory crusher in accordance with claim 6 wherein the face
to face arranged upper and lower surfaces of the groove and the
part define annular, partial surfaces of a sphere, a center of the
sphere being a center of the oscillating movement of the main shaft
at the upper end of the main shaft.
8. A gyratory crusher in accordance with claim 6 wherein the sealing
member includes a flangelike part and a sleevelike part within it.
9. A gyratory crusher in accordance with claim 6 wherein a protective
cover is arranged on top of the sealing member and the fixing ring
whereby the contact surfaces between the fixing ring and the protective
cover are inclined in such a way that radially outer edges of the
fixing ring and the protective cover are higher than radially inner
edges of the fixing ring and the protective cover.
10. A gyratory crusher in accordance with claim 1 wherein the
face to face arranged upper and lower surfaces of the groove and
the part define annular, partial surfaces of a sphere, a center
of the sphere being a center of oscillating movement of the main
shaft at the upper end of the main shaft.
11. A gyratory crusher in accordance with claim 10 wherein the
sealing member includes a flangelike part and a sleevelike part
within it.
12. A gyratory crusher in accordance with claim 1 wherein the
sealing member includes a flangelike part and a sleevelike part
within it.
13. A gyratory crusher in accordance with claim 1 wherein the
inner edge of the sealing cover is sealed against the main shaft
via a protective sleeve fitted against the main shaft.
14. A gyratory crusher in accordance with claim 1 wherein between
the sealing member and the main shaft there is at least one changeable
seal ring.
15. A gyratory crusher in accordance with claim 1 wherein between
the sealing member and the main shaft there is a changeable elastic
ring that scrapes the main shaft when the main shaft is raised or
lowered.
16. A gyratory crusher in accordance with claim 1 wherein there
is a channel in the sealing cover, one end of the channel joining
a compressed air pipe arranged outside of a crushing chamber, and
a second end of the channel opening onto the sealing member.
17. A gyratory crusher in accordance with claim 16 wherein the
second end of the channel opens onto the sealing member via a channel
arranged in a fixing ring of the sealing member.
18. A gyratory crusher in accordance with claim 1 wherein a lower
surface of the supporting cone includes a cast surface.
19. A gyratory crusher in accordance with claim 1 wherein a lower
surface of the supporting cone is without a recess machined in it
for sealing.
20. A gyratory crusher in accordance with claim 1 wherein one
or several detachable or adjustable counter weights are attached
to a pole ring on the upper end of the eccentric shaft.
Description TECHNICAL FIELD
The present invention concerns gyratory crushers. More particularly
the invention concerns sealing, by means of which the internal parts
of the crusher are protected against dust entering from outside.
BACKGROUND ART
Gyratory crushers comprise a vertical eccentric shaft with an inclined
inner hole therein. A main shaft, into which a supporting cone is
attached, and which is supported to the frame at its upper part
by means of an upper supporting bearing, is mounted in the hole.
The supporting cone is surrounded on its sides by the frame of the
crusher, an element acting as a wearing part called outer crushing
head being attached to the frame. An element acting as a wearing
part called inner crushing head is attached to the supporting cone.
The inner and outer crushing heads, together, form a crushing chamber,
where the feed material is crushed. When the eccentric shaft is
rotated, the main shaft and, together with it, the supporting cone
get to an oscillating movement, whereby the gap between the inner
and outer head at each point varies during the working cycle. The
smallest gap during the working cycle is called the setting of the
crusher, and the difference between the minimum and maximum gap
is called the stroke of the crusher. Through the magnitude of the
setting and the stroke of the crusher, inter alia the particle size
distribution of the produced crushed material and the production
capacity can be influenced.
Presently, a gyratory crusher can be adjusted by means of a hydraulic
system, so that the main shaft can be moved vertically in relation
to the frame. This makes it possible to change the setting so that
the size of the final product corresponds to the desired one and/or
to maintain the same setting when the crushing heads wear.
Dust particles and other foreign objects from the crushing chamber
must be prevented from entering the bearings of the eccentric shaft
and the main shaft, as well as the primary and secondary gear of
the drive device, and in general the lubricant circuit inside the
crusher, and through that the surfaces of the elements to be lubricated.
In the crushers of prior art, generally used presently, there is
for this purpose a sealing cover around the eccentric shaft and
the drive devices connected with it, attached at its lower edge
to the frame, and above it as an extension a narrower cylindrical
supporting sleeve for the sealing. For the upper edge of the supporting
sleeve, there is an annular recess formed in the lower surface of
the supporting cone. The outer surface of the supporting sleeve
forms a sealing surface, against which a seal ring in the recess
of the supporting cone is pressed. The seal ring glides in its recess
in relation to the supporting cone along a spherical surface. In
addition, when the setting of the crusher is adjusted, the seal
ring glides up and down along the surface of the supporting sleeve.
The ring can also glide around the supporting sleeve against the
surface of the sleeve.
The most essential drawback of this prior art is that the recesses
and grooves formed in the supporting cone for sealing members make
the supporting cone weaker. Other drawbacks of the prior art are
the complicated shape of the lower surface of the supporting cone--and
thus high production costs--as well as the fast wearing of the seal
ring caused by the required great movement of the seal ring.
Because in these constructions known in the art, the sealing member
rises or lowers with the main shaft of the crusher when the vertical
position of the main shaft is adjusted, the consequence is that
also its distance from the upper supporting bearing, that is its
radius of oscillation changes. For this reason, it has been necessary
to dimension the sealing against the cone in this structure as a
compromise between different radii of oscillation, and some clearance
has been reserved to it for extreme positions.
In publication DE 673 351 there has been described a crusher,
in which the sealing cover is sealed against the main shaft so,
that the outer edge of a horizontal sealing member has been fitted
in an internal recess provided in the upper part of the sealing
cover. A drawback of this known solution is, however, that little
by little the oscillating movement of the main shaft causes the
sealing to break, even if it is made of flexible material. Alternatively,
big clearances must be used, whereby the tightness of the construction
will be lost.
In publication DE 1 243 955 there is described a crusher, in which
the lower surface of the outer edge of a sealing member between
the main shaft and the sealing cover is fitted tightly against the
frame of the crusher. In case the main shaft is lifted upwards in
order to change the setting, the sealing member departs from the
surface of the crusher frame.
Publication DE 1 507 573 discloses a crusher, in which the sealing
members between the main shaft and the sealing cover are completely
unprotected from above, and thus subject to dust, whereby the surfaces
wear very quickly. It is also not unambiguously clear from the publication,
how the sealing cover and the sealing member remain in position
when the setting is changed.
DISCLOSURE OF THE INVENTION
General Description
The present invention relates to a crusher.
The most essential feature of the invention is that the sealing
cover is sealed against the main shaft, and shaped so as not to
be broken by the oscillating movement of the main shaft. The tightness
will also be maintained when the setting of the crusher is changed,
because the sealing cover and the sealing member do not move in
relation to the frame when the setting of the crusher is changed.
Also the sealing itself is protected against dust.
A further advantage of the structure in accordance with the present
invention is that the supporting cone can be made stronger, as there
is no need to make any recess for the supporting sleeve of the sealing.
In addition, the supporting cone is more easily manufactured. The
lower surface of the supporting cone can be even left as a cast
surface, and no smooth machined surface is required on it, against
which the sealing would be fitted, as in the structures of prior
art. The sealing structure is also in other respects simpler and
more economical and secure than the known solutions.
As the sealing has been moved from the sealing sleeve inwards against
the main shaft, the circumference of the circle where the sealing
is effected is shorter. For this reason, also the required sealing
member is smaller. Also the speed of the movement of the sealing
member--and thereby the wearing of the sealing member--is reduced.
As in the solution in accordance with the invention there is always
oil in the space below the sealing member, providing the lubrication
of the bearings of the crusher, the same oil is also provided on
the surface of the main shaft below the sealing member. As the main
shaft, along with the wearing of the crushing heads, as a rule must
be raised, the sealing member always receives clean oil free of
dust, thus preventing the wearing of the sealing member.
In a structure in accordance with the present invention, the main
shaft glides in relation to the sealing member, when the vertical
position of the main shaft is adjusted, whereby the radius of oscillation
is independent of the position of the main shaft and always constant.
Therefore the sealing member can be positioned with an optimal clearance
or even without any clearance, whereby also its sealing effect is
good.
The sealing of the internal circumference of the sealing member
can be improved by placing one separate sealing or a plurality of
individual sealings between the internal circumference and the main
shaft. In this way, also the wearing of the internal circumference
of the sealing member can be reduced.
In the structure in accordance with the present invention, the
balancing of the crusher can also be easily provided without increasing
the height of the crusher, because in the structure in accordance
with the invention, there will be more space vacant for the counter
weight. The space vacant below the supporting cone can be utilised,
and the counter weight can be constructed correctly for every stroke.
It is also known to use compressed, in crushers to prevent dust
from entering on the sealing member and therefrom further the bearings
of the machine. In the structure in accordance with the invention,
it is possible to provide the sealing cover with a channel, and
bring the compressed air directly to the sealing.
DESCRIPTION OF DRAWINGS
Enclosed drawings form a part of the description of the invention.
FIG. 1 illustrates one gyratory crusher in accordance with the
present invention.
FIG. 2 shows an enlarged detail of the crusher of FIG. 1.
FIG. 3 shows as enlarged an alternative embodiment of the detail
of FIG. 1.
EXAMPLES
The main parts of the crusher of FIG. 1 are a frame 1 a transmission
mechanism 2 an eccentric shaft 3 a main shaft 4 and a supporting
cone 5 arranged on the main shaft.
An outer crushing head attached to the upper part of the frame
1 and an inner crushing head attached to the supporting cone 5 form
a crushing chamber. To the lower part of the frame there is arranged
the transmission mechanism 2 by means of which the eccentric shaft
3 is rotated.
The lower end of the main shaft 4 is via bearings 6 supported to
an adjusting piston 7 arranged at the lower part of the frame 1.
By leading pressure medium into a cylinder below the adjusting piston
or from the cylinder, the main shaft can be raised or lowered in
relation to the frame.
The upper end of the eccentric shaft 3 is provided with a pole
ring 8 with counter weights. The lower edge of the pole ring is
provided with a bevel gear 9.
The eccentric shaft 3 is covered with a sealing cover 10. The skirt
11 of the outer edge of the sealing cover is tightly fixed to the
lower part of the crusher frame 1. The inner edge 12 is sealed against
the main shaft 4 by means of a sealing member 13. The sealing member
can be shaped e.g. as shown in the drawings.
The sealing cover is dimensioned so that between the main shaft
and the inner edge of the sealing cover there is left a space or
a groove required by the sealing member.
The outer surface of the sealing cover 10 is inclined downwards
and outwards. Thus, no crushed stone is gathered upon it.
In FIG. 2 the structure of the sealing member is shown in more
detail. The sealing member 13 is formed of a flangelike part 13'
and of a sleevelike part 13" within it, extending upwards from
the inner edge of the flangelike part.
Against the inner circumference of the sealing member 13 there
can be a cylindrical protective sleeve 14 pressing tightly against
the main shaft.
The inner edge 12 of the sealing cover 10 forms an annular flange.
A fixing ring 16 is arranged above the flange so that a groove 17
is formed between for the sealing member 13. The groove has a form
of the sealing member, but it is sideways wider than it, so the
upper and lower surfaces of the flange part 13' of the sealing member
13 set tightly against the groove, but, however, can move sideways
in it along the movement of the main shaft 4.
The face to face arranged upper and lower surfaces of the groove
17 of the sealing cover 10 and the flangelike part 13' of the sealing
member are parts of a spherical surface, the centre of which is
the centre of the oscillating movement of the main shaft at the
upper end of the main shaft 4.
On top of the fixing ring 16 of the sealing member there is, in
addition, a protective ring 18 made of some elastic material.
A channel 19 is formed in the sealing cover 10 the main part of
which is parallel with the cover and joins a channel 20 of the fixing
ring 16 which again opens at the lower surface of the fixing ring
against the sealing member 13. Through the channels 19 20 compressed
air can be blown to the sealing member from a pipe 21 for removing
dust from the upper surface of the sealing member 13 gliding against
the groove 17.
In addition, the sealing member 13 can be provided with one or
several separate seal rings 22 23 which seal the gap between the
sealing member and the main shaft or the sealing member and the
protective sleeve 14. The seal ring 23 can be a changeable, elastic
ring, that scrapes the main shaft when the main shaft is raised
and lowered.
When the main shaft 4 is making its oscillating movement, the centre
of mass of the main shaft and the masses fastened to it changes
its position. Therefore the masses connected with the pole ring
8 of the eccentric shaft of the crusher must be dimensioned so as
to balance the forces caused by the movement of the main shaft and
the centre of mass of the masses connected with it, and thus decrease
the swinging of the crusher.
With different stroke movements, the path of movement of the main
shaft and the centre of mass of the masses connected with it is
different. For this reason, the position or magnitude of the masses
connected with the pole ring of the eccentric shaft should be adjustable.
In a structure in accordance with the invention, more room will
be left above the pole ring 8 and thus detachable or adjustable
counter weights 24 (FIG. 1) can be attached to the pole ring, and
these counter weights can be added, removed or moved according to
need in order to balance the crusher with different stroke movements.
The protective ring 18 can be also replaced e.g. with a rubber
bellow. This kind of a rubber bellow can extend to be tightly against
the protective sleeve 14 or the main shaft 4 itself.
FIG. 3 illustrates an alternative embodiment of the sealing arrangement.
There the elastic protective ring 18 on top of the fixing ring 16
has been replaced by a protective ring 25 which is attached to the
sealing element 13 so, that the lower surface of the protective
ring is in contact with the protective cover. The contact surface
26 between the sealing member and the protective ring is conical
or a part of a spherical surface.
Thus, the protective ring oscillating with the seal ring maintains
its contact with the fixing ring 16. The protective ring 25 is attached
to the upper surface of the sleeve part 13" of the sealing
member, whereby it properly also protects the seal ring from dust.
In the embodiments of both the FIG. 2 and FIG. 3 the upper and
lower surfaces of the sealing member 13 and the groove 17 do not
necessarily have to be exactly spherical surfaces, but also slightly
inclined conical surfaces following closely to these kinds of spherical
surfaces can be used.
Because the distance between the sealing member and the centre
of the oscillating movement of the main shaft is in practice long
compared with the length of the flangelike part 13' of the sealing
member, the spherical surfaces of the face to face upper and lower
surfaces of the groove 17 of the sealing cover 10 and the flangelike
part 13' of the sealing member can be replaced by conical surfaces
forming with the centre axis of the crusher an angle which is smaller
than 90.degree.. It is essential that the outer surfaces of both
the groove 17 of the sealing cover 10 and the flangelike part 13'
of the sealing member are higher up than their inner edges.
The sealing member can also be shaped so that there is no sleevelike
part 13" in it. Thereby the separate seal rings 22 23 can
be arranged in a narrow area on the inner edge of the sealing member.
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