The present invention refers, in general terms, to a conical crusher of the type comprising an upper housing in which interior operates a cone head driven in an eccentric oscillating motion around a fixed vertical tubular axle, said cone head being axially journalled at the upper end of a supporting rod located inside the tubular axle and which is axially and selectively displaceable in order to vary the opening of a crushing cavity defined between the cone head and the upper housing.
The invention is particularly related to the means responsible for bearing and adjusting the position of the cone head in relation to the upper housing.
Different constructive solutions are known for supporting the cone head of a crusher of the type considered herein.
One of the known solutions may be found schematically illustrated in
The tubular eccentric 80 is axially and inferiorly seated on the structure 10 of the conical crusher by a set of axial bearings 83, said tubular eccentric 80 being provided with a ring gear 84 which is geared to a pinion 91 of a drive mechanism 90, suitably mounted on structure 10 and which will not be described in detail since it does not make part of the present invention. The rotation drive of the tubular eccentric 80 by the driving mechanism 90 causes the oscillation of the cone head 70 around the fixed tubular axle 30, providing the crushing of the material inside the crushing cavity “CB”.
Inside the tubular axle 30 is mounted a supporting rod 40, having an upper end 41 which projects outward from the tubular axle 30 to receive a spherical bearing 50 onto which is seated the spherical end 71 of the cone head 70.
The supporting rod 40 presents a lower end 42 projecting beyond the lower end of the tubular axle 30 and to which is coupled an actuator, generally in the form of a piston 60, located inside a hydraulic cylinder 11 formed in the lower portion of the structure 10 of the conical crusher, said hydraulic cylinder 11 defining, with piston 60, a hydraulic ram dimensioned to allow, when driven, the vertical axial displacement of the supporting rod 40, in order to provide the axial displacement of the cone head 70 to different operational positions, adjusting the opening of the crushing cavity “CB”.
Although not illustrated herein for not making part of the present invention, it should be understood that the hydraulic cylinder 11 may be coupled to a pressure limiting valve or to a hydraulic accumulator, to function as a protection device against overloads in the crushing cavity “CB”, allowing the descending displacement of the cone head 70, increasing the distance from the upper housing 20 and increasing the opening of the crushing cavity “CB” to automatically reduce the crushing overload when the adjustment hydraulic system detects said overload.
The setting of the opening of the crushing cavity “CB” is carried out by the vertical displacement of the cone head 70 by axial displacement of the supporting rod 40.
The rigid mounting of the supporting rod 40 in the construction of
Considering that the supporting rod 40 is fixed in the radial direction, the spherical bearing 50 that supports the cone head 70 is subject to high oscillatory amplitudes during the crusher operation. Although said axial bearing of the cone head 70 is made with provision of oil in the spherical bearing 50, the relatively low rotation speed of the conical crushers does not allow the formation of a hydrodynamic wedge in the axial bearing. The loads to which the axial bearing 50 is subjected as a function of the radially fixed mounting of the supporting rod 40, together with the difficulty in forming a hydrodynamic wedge in the axial bearing of the cone head 70, allows the occurrence of metal-metal contact, with the consequent loss of power caused by friction and of lifespan of the bearing itself, reducing the intervals between equipment stop for replacing wear parts. These known solutions thus present the inconvenient of subjecting the axial bearing 50 to excessive loads, which tend to cause an accelerated wear of said component, due to the difficulty in obtaining an adequate lubrication by the simple supply of oil to the bearing.
Another inconvenient of the known solutions refers to the fact that the cone head is not prevented from rotating in the same direction of the tubular eccentric, when the conical crusher operates with zero load. In this condition, the cone head tends to be rotatively dragged by the spin of the tubular eccentric, gaining speed and being subjected to a sudden and wearing braking upon the restart of material feeding into the crushing cavity “CB”.
Due to the drawbacks mentioned above and related to the prior art solution, it is an objective of the present invention to provide a conical crusher of the type illustrated in
It is a further objective of the present invention to provide a conical crusher as mentioned above, which presents a lubrication that provides the formation of a hydrostatic support in the axial bearing of the cone head, in order to prevent the metal-metal contact, thereby increasing the lifespan of the bearing components and allowing the latter to present smaller dimensions.
It is also a further objective of the present invention to provide a conical crusher as mentioned above, whose cone head is prevented from rotating around its axial axis, in the same direction of rotation of the tubular eccentric.
According to the present invention, the conical crusher comprising the elements considered in the construction illustrated in
The invention will be described below with reference being made to the attached drawings, given by way of example of constructions for a conical crusher and in which:
a represents an enlarged detail illustrating the formation of the spherical joint “R” between the lateral walls of the piston and of the hydraulic cylinder;
As already mentioned, the invention is applied to a conical crusher of the type illustrated in
As illustrated in
The hydraulic cylinder 11 has a lateral wall 13a generally defined by a removable cylindrical sleeve 13, internally lining said hydraulic cylinder 11. Inside the tubular axle 30 is provided a supporting rod 40 that has an upper end 41 carrying a spherical bearing 50 and a lower end 42 carrying a piston 60, which is selectively and axially displaceable inside the hydraulic cylinder 11, producing a corresponding vertical displacement in the supporting rod 40 and in the spherical bearing 50, as described further below. Inside the upper housing 20 is provided a cone head 70 provided with a lining 70a and which forms, with the upper housing 20, a crushing cavity “CB”, the cone head 70 being internally and superiorly provided with a spherical end 71, to be seated onto the spherical bearing 50, and further being radially and inferiorly journalled, with an external bushing 82, around a tubular eccentric 80 which, in turn, is rotatively mounted around the tubular axle 30 with the placement of an inner tubular bushing 81 between the tubular axle 30 and the tubular eccentric 80. It should be understood that the axial bearing of the cone head 70 onto the upper end 41 of the supporting rod 40 may be obtained by assemblies other than that illustrated herein by way of example.
The tubular eccentric 80 is provided with a ring gear 84 geared to a pinion 91 of a drive mechanism 90 mounted on structure 10, as already mentioned in relation to the structure illustrated in
In order that the supporting rod 40 may oscillate, following the oscillation of the cone head 70, the first has its upper end 41 articulated to the cone head 70 by means of the spherical end 71 of the latter and the spherical bearing 50, and with the lower end 42 being articulated to the structure 10 by means of the piston 60.
In the construction illustrated in
The crushing force resulting from the oscillating motion of the cone head 70 is transmitted, through the rod 40, to the piston 60, and is supported by the oil pressure generated in the hydraulic cylinder 11. The rod 40, following the cone head 70 motion, induces a slight oscillatory motion on piston 60. The outer edge of piston 60, where is inserted a sealing 62, has a spherical shape, allowing a vertical displacement during piston oscillation, without interfering with the lateral wall 13a of the cylindrical sleeve 13 of the hydraulic cylinder 11. Another possible construction would be to provide an articulated coupling between the lower end 42 of the supporting rod 40 and the piston 60, the latter in this case having a cylindrical lateral wall 61 cooperating with the lateral wall 13a of the hydraulic cylinder 11.
As better illustrated in
In this type of construction, in which the vertical motion of the supporting rod 40 is effected by the piston 60, the hydraulic cylinder 11 is hydraulically pressurized from a source of pressurized fluid (not illustrated) which is in communication with the interior of the hydraulic cylinder 11 below piston 60 through a nozzle 15 which may be provided in the cover 12. As mentioned before in relation to the prior art, piston 60 operates hydraulically, not only as the vertical thrusting element of the supporting rod 40, but also as a safety device against overloads. The source of pressurized fluid and the hydraulic cylinder 11 may be associated with a pressure limiting valve or to a hydraulic accumulator (not illustrated and of known existence and function) to release hydraulic fluid, allowing the descent of the cone head 70 and the opening of the crushing cavity “CB” upon the occurrence of an overload condition.
The piston 60 presents an axial extension 60a, in which is rotatively, axially and angularly fixed the lower end 42 of the supporting rod 40, said axial extension 60a being positioned inside an enlarged lower end 35 of the axial through hole 30a of the tubular axle 30, said enlarged lower end 35 being provided with at least one longitudinal cutout 35a, in which runs a key 65 radially fitted in the axial extension 60a of piston 60, locking any rotation of the latter in relation to the tubular axle 30 and, consequently, also in relation to the structure 10, yet allowing piston 60 to oscillate together with the supporting rod 40.
It should be noted herein that the oscillation of the supporting rod 40 around the spherical joint “R”, defined herein by both the lateral wall 61 of piston 60 and the lateral wall 13a of the cylindrical sleeve 13 of the hydraulic cylinder 11, due to the geometry of the conical crusher, is limited to very reduced values which are defined by the eccentricity of the tubular eccentric 80, with the radial gap between the supporting rod 40 and the tubular axle 30 having to be dimensioned slightly larger than said oscillation eccentricity of the cone head 70 and of the spherical bearing 50, in order to avoid that the supporting rod 40, particularly the upper region thereof, touches the tubular axle 30.
As mentioned before in relation to
The construction proposed by the present invention to provide the oscillation of the supporting rod 40, allowing it to follow the oscillation of both the cone head 70 and the spherical bearing 50, leads to a substantial reduction of the articulation motion in the region of the spherical bearing 50, said reduction of motion achieving an order of about 6 times less than that found in the present axial spherical bearings mounted on radially fixed supporting rods. The reduction in relative motion at the spherical bearing 50 reduces its wear, allowing the use of the conventional lubrication of the prior art.
However, the lubrication of the spherical bearing 50 may be carried out in order to provide a hydrostatic support for the cone head 70. In this case, the supporting rod 40 is provided with a central axial channel 44 having a lower connected, usually by means of a flexible hose 45, to a source of high-pressure pressurized lubricating oil (not illustrated) and an upper end connected to at least one radial channel 54 of the spherical bearing 50. The lubricating oil at high-pressure is forced, through the central axial channel 44 and radial channel 54, toward the face of the spherical bearing 50, onto which is seated spherical end 71 of the cone head 70, defining a hydrostatic support between the spherical end 71 and spherical bearing 50, preventing the direct contact between the two components of the axial journal of the cone head 70.
Besides the journaling and lubrication aspects mentioned above, the invention also addresses the problem created when the cone head is left to rotate together with the tubular eccentric 80, being dragged by the latter in the same rotation direction, when the crushing cavity “CB” is not being fed with material to be crushed (zero load operation). In this condition, when the material is fed to the crushing cavity “CB”, the cone head 70 is stops suddenly. The high inertial forces of the cone head 70 causes, with the sudden stop, an undesirable wear of the linings of the crushing cavity “CB”.
With the purpose of eliminating this drawback, the present invention provides a locking hub mechanism 100 mounted inside the cone head 70 which is operatively coupled to the spherical bearing 50, to allow the usual slow rotation of the cone head 70 in the opposite direction of rotation of the tubular eccentric 80 upon the crushing operation of a load of material continuously fed to the crushing cavity “CB”, but preventing the cone head 70 from rotating in the same rotation direction of the tubular eccentric 80. Thus, when operating with zero load, the cone head 70 is prevented from being rotationally dragged by the rotation of the tubular eccentric 80, remaining rotationally stationary and waiting for the restart of the feeding of material to be crushed to then start, without any sudden stops, its slow rotation in the opposite direction of rotation of the tubular eccentric 80.
The locking hub mechanism 100 is comprised, according to an exemplary form illustrated in
The locking hub device 100, in the illustrated example, further presents rotation blocking means defined by a plurality of cutouts 104 formed on the outer edge of the inner race 102 and having a variable depth defined by a tapered wall 104a, with each of the cutouts 104 lodging a roller 105 which remains simultaneously seated, like a wedge, onto the inner edge of the outer race 101 and on the tapered wall 104a of the respective cutout 104. Each roller 105 is constantly and elastically forced, by a set of spring 106 and rod 107, to the shallowest region of the cutout 104, turned to the direction of rotation of the tubular eccentric 80.
With this construction, when the crusher is operating with zero load, the tubular eccentric tends to rotate the cone head 70 and the inner race 102 of the locking hub mechanism in the same direction, forcing the rollers 105 to the shallowest region of the cutouts 104, locking the outer race 101 to the inner race 102 and preventing the rotation of the cone head 70 in this direction. In the opposite direction, the outer race 101 forces the rollers 105 toward the deepest region of the cutouts 104, against the force of the spring 106, minimizing the friction of the rollers 105 with the races and allowing the rotation of the cone head 70.
Although only one embodiment of the invention has been illustrated, it should be understood that modifications in the shape and arrangement assembly of the components may be made without departing from the constructive concept defined in the accompanying claims.
Number | Date | Country | Kind |
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PI 0504725-0 | Oct 2005 | BR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/BR2006/000213 | 10/11/2006 | WO | 00 | 10/16/2007 |