Anti-spin system for the head of a cone crusher

1. An anti-spin system for the head of a cone crusher of the type which comprises a structure ( 10 ), in which are mounted an upper housing ( 20 ) and a vertical axle ( 30 ) having a free upper end ( 31 ); an eccentric element ( 40 ) mounted around the vertical axle ( 30 ), to be rotated by a drive mechanism ( 50 ); and a cone head ( 60 ), disposed in the interior of the upper housing ( 20 ) and being axially and rotatively supported on the structure ( 10 ) above the free upper end ( 31 ) of the vertical axle ( 30 ) and radially and rotatively supported around the eccentric element ( 40 ),

wherein said cone head ( 60 ) has a mass center,

said anti-spin system further comprising a braking bush ( 70 ), carried by one of the parts defined by the cone head ( 60 ) and by the structure ( 10 ) and an annular shoe ( 80 ) carried by the other of said parts, the braking bush ( 70 ) and the annular shoe ( 80 ) being pressed against each other, by action of the inertial centrifugal force (T) acting on the mass center of the cone head ( 60 ) upon “no-load” operation of the crusher, so as to generate a braking friction force (R 1 ) opposite to a dragging friction force (R 2 ) generated between the cone head ( 60 ) and the eccentric element ( 40 );

characterized in that said braking bush ( 70 ) and annular shoe ( 80 lie an axial distance (A) from the mass center of the cone head ( 60 ) smaller than an axial distance (B) between said mass center and the region in which acts the dragging friction force (R 2 ) in the minimum eccentricity region of the eccentric element ( 40 ), said braking friction force (R 2 ) being superior to the dragging friction force (R 2 ) preventing the cone head ( 60 ) from being rotationally dragged by the eccentric element ( 40 ).

2. The system as set forth in claim 1 , characterized in that the braking bush ( 70 ) and the annular shoe ( 80 ) are carried by the respective parts of cone head ( 60 ) and structure ( 10 ), in a region of said parts disposed in the interior of the cone head ( 60 ) and axially positioned between the axial and radial supporting regions of the cone head ( 60 ) on the structure ( 10 ) and on the eccentric element ( 40 ), respectively.

3. The system as set forth in claim 2 , characterized in that at least one of the parts of braking bush ( 70 ) and annular shoe ( 80 ) is removably mounted to the respective part of cone head ( 60 ) and of structure ( 10 ) which carries it.

4. The system as set forth in claim 3 , characterized in that each of the parts of braking bush ( 70 ) and annular shoe ( 80 ) presents a contact cylindrical surface ( 71 , 32 a ), the contact cylindrical surface ( 71 ) of that part carried by the cone head ( 60 ), surrounding and confronting the innermost contact cylindrical surface ( 32 a ) of that other part carried by the structure ( 10 ), in order to be radially pressed and frictioned against the innermost contact cylindrical surface ( 32 a ), in a tangential contact region diametrically coincident with a region of minimum eccentricity of the eccentric element ( 40 ), by the inertial centrifugal force (T) acting on the cone head ( 60 ) when the crusher is in the “no-load” operation.

5. The system as set forth in claim 4 , characterized in that the braking bush ( 70 ) is removably mounted in the interior of the cone head ( 60 ) and has a radially inner contact cylindrical surface ( 71 ), the annular shoe ( 80 ) being defined in a region of the structure ( 10 ) and having its radially outer contact cylindrical surface ( 32 a ) confronting the contact cylindrical surface ( 71 ) of the braking bush ( 70 ).

6. The system as set forth in claim 5 , characterized in that the annular shoe ( 80 ) has its contact cylindrical surface ( 32 a ) defined in a support ( 32 ) affixed to the vertical axle ( 30 ).

7. The system as set forth in claim 6 , characterized in that at least one of the contact cylindrical surfaces ( 71 , 32 a ) is provided with oil release grooves ( 72 , 32 b ).

8. The system as set forth in claim 7 , characterized in that at least one of the contact cylindrical surfaces ( 71 , 32 a ) is provided with at least one circumferential channel ( 76 ) in which is fitted and retained a ring ( 90 ) in a material of high-friction coefficient and which projects radially from the contact cylindrical surface which carries it, so as to provide frictional contact with the other contact cylindrical surface, in a region axially aligned with that of minimum eccentricity of the eccentric element ( 40 ) upon “no-load” operation of the crusher.

9. The system as set forth in claim 7 , characterized in that at least one of the contact cylindrical surfaces ( 71 , 32 a ) is provided with at least one circumferential channel ( 76 ) in which is fitted and retained a ring ( 90 ), in a material of high-friction coefficient and which projects radially from the contact cylindrical surface which carries it, so as to continuously provide frictional contact with the other contact cylindrical surface, in a region axially aligned with that of minimum eccentricity of the eccentric element ( 40 ), upon “no-load” and “on-load” operations of the crusher.

10. The system as set forth in claim 9 , characterized in that the eccentric element ( 40 ) has its minimum eccentricity region provided with a recess ( 45 ), which extends downwards from an upper edge of the eccentric element ( 40 ) so as to define, in a lower portion of said region, a bearing surface ( 46 ) for the cone head ( 60 ) with an axial extension (X) which is reduced but sufficient to support the inertial centrifugal force (T) which actuates on the cone head ( 60 ) upon “no-load” operation of the crusher.