Abstrict A cone crusher for crushing stones comprises an outer shroud housing
a shaft driven of conical swinging motion at the middle portion
whereof there is provided a crushing or milling cone, cooperating
with a shroud conical ring to define an upward widening space therebetween,
a rotating bush being provided for housing a hydraulic piston supporting,
through an axial roller bearing, the bottom end of the shaft arranged
substantially concentrical to the piston.
Claims I claim:
1. A cone crusher for crushing stones and the like, comprising
an outer shroud enclosing a space, a substantially vertical shaft
within said space and driven with a conical swinging motion, said
shaft having a downwardly diverging crushing cone at a middle portion
thereof, on said shroud a conical ring spacingly arranged around
said crushing cone and having a smaller taper than said crushing
cone to define an upwardly widening space therebetween, a rotatory
bushing member surrounding said shaft below said crushing cone and
rotatably supported on said outer shroud, said bushing member having
a circular outer periphery defining an axis of rotation and a cylindrical
inner cavity having an axis eccentric with respect to said axis
of rotation, said cavity receiving a lower end portion of said shaft
and having a closed bottom, a piston axially slidable within said
inner cavity and arranged below said shaft, bearing means between
said shaft and said piston for rotatably supporting said shaft on
said piston on one side thereof facing said shaft, said piston having
another side thereof opposite to said one side and forming a cylinder
chamber with said closed bottom, a hydraulic system for supplying
pressure fluid into said cylinder chamber thereby to hydraulically
support said piston and said shaft thereon, transmission means on
said rotary bushing member for imparting rotation thereto thereby
to impart rotation to said bushing member about said axis of rotation
thereof and to impart an eccentric rotatory movement to said piston
and said shaft thereon, said hydraulic system including a rotary
joint connected to said rotary bushing member, said rotary joint
having a mounting flange for connection to said closed bottom of
said cavity, a fixed channel extending through said mounting flange
for the passage of pressure fluid from said hydraulic system into
said cylinder chamber of said cavity, a seat in said mounting flange,
rotary seals in said seats and interposed between said fixed channel
and said mounting flange, a plate member surrounding said fixed
channel and providing a clearance therebetween for bleeding off
pressure fluid therethrough.
Description BACKGROUND OF THE INVENTION
This invention relates to a cone crusher for crushing stones and
the like.
As is known, long shaft cone crushers comprise essentially an outer
shroud formed of two pieces, namely a bottom shroud and top shroud,
which are connected to each other by means of strong bolts which
allow the material to flow from top to bottom.
The shroud has mounted internally a suspended or supported shaft
which undergoes an eccentric movement at the lower portion thereof,
thereby the shaft performs a conical swinging movement.
At a middle portion of the shaft, there is provided a conical part,
called the crushing cone, which widens out from top to bottom and
is located at a conical milling ring provided on the shroud inside.
The conical milling ring has a smaller taper than the milling or
crushing cone, such that the space or clearance between the cone
and ring widens towards the top.
Moreover, cone crushers are equipped with devices for raising and
lowering the crushing cone with respect to the crushing ring in
order to increase or decrease the space separating the cone from
the ring and thus throttle the passage area and consequently the
size of the resulting product.
The most critical operation of conventional crushers is in fact,
and in general, the cone height adjustment, which is accomplished
by hydraulic power. More precisely, the shaft carrying the crushing
stone floats on a pressurized oil cushion which constitutes the
fixed hydraulic raising group, a set of bevel gears being provided
within the machine along with a countershaft driving the cam which
imparts to the shaft bottom portion the desired eccentric rotation
which provides the cited conical swinging movement.
In addition to the above, seating or the like means must be provided
for supporting the bottom portion of the shaft and withstand the
axial push, which means are unavoidable subjected to a fast wear
rate owing to the continuous oscillation of the shaft bottom or
lower end.
SUMMARY OF THE INVENTION
This invention sets out to eliminate the problems encountered with
conventional crushers by providing a cone crusher which, while retaining
the general configuration of conventional cone crushers, has novel
features effective to greatly reduce all of the constructional and
wear problems normally affecting cone crushers.
Within that general aim, it is possible to arrange that the cone
crusher according to this invention makes provision for the utilization
of drive belts for the transmission of the rotary motion, which
belts are more reliable than the gear drive in this type of application.
It is further possible to arrange that the cone crusher of this
invention can successfully withstand the violent shocks which are
unavoidably experienced in the crushing or milling chamber on account
of the severe and discontinuous loads to which the machine is subjected
by the nature of its work.
It is, moreover, possible to arrange that the cone crusher for
stones and the like, according to the invention, has a simplified
construction, requires no special or complex maintenance procedure,
and is highly competitive from an economical standpoint.
According to one aspect of the present invention, there is provided
a cone crusher for crushing stones and the like, comprising an outer
shroud enclosing a space, a shaft within said space and driven with
conical swinging motion, at a middle portion thereof said shaft
having a downwardly diverging crushing cone, around said crushing
cone on said shroud, a conical ring having a smaller taper than
said crushing cone to define an upwardly widening space therebetween,
characterized in that the crusher further comprises a bushing arranged
to rotate about its own axis and defining with its inside a cavity
eccentric with respect to said axis of rotation, a hydraulic piston
within said cavity and in sealed relationship therewith, said piston
supporting, with the interposition of rolling means, the bottom
end of said shaft arranged substantially concentrical to said piston.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will be more readily
understood from the following detailed description of a preferred
but not limitative embodiment of a cone crusher for stones and the
like, with reference to the accompanying illustrative drawings,
where:
FIG. 1 shows an axial sectional view of the cone crusher according
to the invention;
FIG. 2 is an enlarged scale detail view of the rotary joint provided
for the hydraulic system; and
FIG. 3 shows, on an enlarged scale, the connection between the
clamping nut and crushing or milling cone.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the cited drawing figures, the cone crusher for
crushing stones and the like rocky material, according to this invention,
comprises an outer shroud, generally indicated at 1 which is formed
from a top or upper part 1a and bottom or lower part 1b, both parts
being held tightly together by a bolted connection. The top part
1a also defines a hopper 2 for loading the material to be crushed.
Inside the cited shroud 1 there is provided a shaft 3 in proximity
to the top end whereof a ball swivel joint 4 is provided which is
accommodated in a mating seat or socket provided in the top part
1a.
At a middle portion of said shaft 3 there is provided a crushing
or milling cone 5 the connection whereof to the shaft will be described
hereinafter, the crushing cone having its major base facing downwards;
at said crushing cone 5 on the part 1a of the shroud 1 there is
provided a conical ring 6 which has a smaller taper than the crushing
cone 5 thereby a space or clearance is established at 7 which widens
out towards the top part and assists in conveying the material to
be crushed from the hopper 2 downwards.
The peculiar feature of the invention is that it provides a bushing
10 set for rotation about its own axis and defining on its inside
an eccentrical cavity 11 accommodating a hydraulic piston 12 in
sealed relationship.
More specifically, the bushing 10 which has a pulley 13 at its
lower portion for connection to a belt drive which transmits the
rotary motion, is supported on the part 1b of the shroud 1 through
a first tapered roller bearing, indicated at 14 which is capable
of withstanding both the axial thrust imparted by the shaft and
the radial thrust transmitted by the eccentricity; the first tapered
roller bearing may, however, be replaced with a radial bearing and
an axial bearing, in combination.
The eccentrical motion is transmitted to the bottom end of the
shaft 3 received in the eccentrical cavity 11 through a tilting
roller bearing 15 having on its inside a bushing 16 made of an antifriction
material, which bushing allows for the axial displacement of the
shaft, as will be explained hereinafter, the bearing being mounted
on the inside walls of the eccentrical cavity 11.
The shaft 3 rests with its bottom end on the cited hydraulic piston
12 with the interposition of an axial roller bearing, indicated
at 17.
An essential feature is that the shaft 3 is arranged concentrically
with respect to the piston 12 which is moved of eccentrical motion,
thereby the axial roller bearing 17 which bears the axial thrust
of the shaft 3 is as far as possible free of rubbing actions and
overheating, such as would be unavoidable with a traditional fixed
hydraulic piston system.
In fact, with the cone crusher according to this invention, the
piston 12 is rotated eccentrically owing to the bushing 10 which
is formed with the cited eccentrical cavity 11 accommodating the
piston, rotating about its own axis.
Into the chamber 12a which is defined in the eccentrical cavity
11 below the piston 12 by the closed bottom of the cavity 11 there
is fed pressurized oil from a hydraulic system which will be described
hereinafter.
In the cited chamber 12a, there is provided a body 20 of an elastic
material which is resistant both to oil and continued and sudden
changes of dimension and has the function of dampening the shocks
transmitted by the crushing chamber owing to the unavoidably severe
and discontinuous nature of its work. By contracting its own volume
under these shocks, the body 20 is effective to reduce or absorb
the hammer shocks, thus protecting the bearings as well as the hydraulic
system and the structure.
To introduce pressurized oil into the chamber 12a defined within
the eccentrical cavity 11 a rotary joint is required effective
to withstand high rates of rotary sliding movement and severe pressure
shocks.
Such a joint, as illustrated in FIG. 2 has a mounting flange 30
for attachment to the bottom of the chamber 12a, inside which a
passageway is defined for the fixed channel, as indicated at 31.
Between said fixed channel 31 and the seat specially provided in
the flange, there are interposed rotary seals 32 of a type known
per se; furthermore, and here resides an essential aspect of the
invention, at the ends of the channel 31 proximate to the chamber
12a, a small plate 33 is provided which closely surrounds, without
actually contacting it, the channel 31 in such a manner as to leave
an extremely reduced clearance 34 for the oil to pass therethrough.
Thus, any overpressure which might build up inside the chamber 12a
cannot discharge itself freely against the rotary seals, which would
be quickly damaged, and the oil can be simply bled off between the
small annular slit 34 defined between the plate 33 and channel 31
thereby the seals will be adequately protected.
Moreover, the seals may be two or three in number, such that all
of them contribute to the sealing action, and an adequate lubrication
is provided to prevent the seals from drying in time and losing
their inherent elastic and sealing properties.
The cone crusher according to the invention further comprises a
hydraulic control for the axial displacement of the shaft, that
is for adjusting the gap between the crushing cone and ring. This
is accomplished through the provision of a cylinder-piston unit,
indicated at 40 the rod 41 whereof is interposed between the cylinder-piston
and the top end of the shaft 3. The fluid, through a line 42 is
taken out of the machine, where another hydraulic apparatus, indicated
at 43 and known per se, measures the increase or decrease of the
amount of liquid displaced by the piston 40 and accordingly the
amount of displacement of the shaft 3 in one or the other direction;
this enbales the machine to be remote controlled, if desired.
A further peculiar feature of the invention resides then in the
means for securing the crushing cone 5.
The crushing cone 5 as usual with the machines in question, must
be replaced when worn out, and therefore, it used to be supported
in general by a conical support and clamped by means of a nut provided
with threads such that the nut was in practice run and set by rotation
of the shaft 3.
This resulted in the clamping or retaining nut, whenever the crushing
cone had to be replaced, being overtightened onto the crushing cone,
such that the nut had to be cut because it could not be removed,
not even with mechanical aids. In many cases, this resulted in the
shaft becoming damaged, since it was difficult to cut the nut without
affecting the shaft at the same time.
To eliminate such drawbacks, in the cone crusher of this invention,
between the crushing cone 5 and retaining or clamping nut 50 there
is interposed a hollowed ring 51 which is provided, at the top and
bottom, with notches or recesses 52 whereinto pawls 53 are inserted
which accomplish the rotary connection between the nut and crushing
cone, which allows the crushing cone to be clamped in a quite conventional
manner.
Said hollowed ring 51 however, is first of all spaced apart from
the shaft 3 and made of a material which makes the cutting of the
ring much easier, such that when the crushing cone must be replaced
it is sufficient to cut the ring to practically break the tight
connection between the nut and crushing cone, thereby, once the
ring has been removed, the nut can be easily threaded out and the
crushing cone 5 replaced.
As can be seen, therefore, the invention provides an intervening
element, represented by the ring 51 which can be removed or suitably
shaped for an easy cutting thereof and facilitated disassembly procedures.
The cone crusher of this invention operates in practice in a similar
manner to known crushers of this type; in fact, once the gap or
clearance has been adjusted by repositioning the shaft axially,
the crushing or milling operation is initiated by controlling the
bushing 10 to rotate, which bushing, through its eccentrical cavity
11 will transmit the desired conical swinging motion to the shaft
which, by rotating concentrically to the hydraulic piston 12 is
not subjected to rapid wear or excessive overheating.
Moreover, and similarly to conventional crushers, in the oil supply
system, there is provided an expansion box indicated at 60 having
the function of damping any hydraulic hammer shocks that might propagate
through the oil line.
The introduction of pressurized oil into the chamber 12 further
enables the shaft 3 to be positioned at will in height, which adjustment
can also be remotely controlled by virtue of the cylinder-piston
40 acting also as a sensor at the top end of the shaft.
The invention as described is susceptible to many modifications
and variations within the scope of the instant inventive concept.
Optionally, a pin may be provided which extends rigidly with and
concentrically to the piston 12; with said pin there would engage
a radial bearing acting on the inner wall of the piston to damp
any radial efforts developed by the bushing 16 wear. Furthermore,
a seating support of an antifriction material is provided between
the bottom end of the shaft 3 and the bearing 17.
Furthermore, all of the details may be replaced by other technically
equivalent elements. |