Gyratory crusher frame

A gyratory crusher frame part and a gyratory crusher include a topshell and spider assembly configured to minimize stress concentrations. An annular flange is formed at the junction between a lower region of each spider arm and an upper region of the topshell. Optimization of loading force transfer and a reduction in stress concentration is achieved by positioning the spider arms radially inward relative to an outer circumferential perimeter of the flange.

RELATED APPLICATION DATA

This application is a § 371 National Stage Application of PCT International Application No. PCT/EP2013/055546 filed Mar. 18, 2013 claiming priority of EP Application No. 12162974.5, filed Apr. 3, 2012.

TECHNICAL FIELD OF INVENTION

The present invention relates to a gyratory crusher frame part and in particular, although not exclusively to a topshell and spider assembly forming an upper region of the crusher frame.

BACKGROUND OF THE INVENTION

Gyratory crushers are used for crushing ore, mineral and rock material to smaller sizes. Referring toFIG. 1, a typical crusher comprises a frame100having an upper frame101and a lower frame102. A crushing head103is mounted upon an elongate shaft107. A first crushing shell105is fixably mounted on crushing head103and a second crushing shell106is fixably mounted at top frame101. A crushing zone104is formed between the opposed crushing shells105,106. A discharge zone109is positioned immediately below crushing zone104and is defined, in part, by lower frame102.

Upper frame101may be further divided into a topshell111, mounted upon lower frame102(alternatively termed a bottom shell), and a spider114that extends from topshell111and represents an upper portion of the crusher. Spider114comprises two diametrically opposed arms110that extend radially outward from a central cap112positioned on a longitudinal axis115extending through frame100and the gyratory crusher generally. Arms110are attached to an upper region of topshell111via an intermediate annular flange113that is centred around longitudinal axis115. Typically, arms110and topshell111form a unitary structure and are formed integrally.

A drive (not shown) is coupled to main shaft107via a drive shaft108and suitable gearing116so as to rotate shaft107eccentrically about longitudinal axis115and to cause crushing head103to perform a gyratory pendulum movement and crush material introduced into crushing gap104.

Example gyratory crushers having the aforementioned topshell and spider assembly are described in U.S. Pat. No. 2,832,547; US 2002/017994; WO 2004/110626 and US 2011/0192927.

In order to maximise the opening into the crushing zone, it is conventional for the spider arms110to extend from the annular flange113at the flange outermost perimeter. As the flange113extends radially outward beyond the circumferential wall of the topshell111, reinforcements are typically required on the external facing surface of the topshell walls being positioned directly below the spider arms111.

These reinforcing ribs that act to transmit the axial forces imparted onto the topshell111from spider110are necessary due to the non-optimised alignment of the spider arms111and the circumferential wall of the topshell. These ribs are disadvantageous as they both add additional weight to the crusher and increase complexity of manufacturing.

Accordingly, what is required is a gyratory crusher frame that addresses the above problem.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a gyratory crusher frame and a gyratory crusher that is both more convenient to manufacture, is more lightweight and minimises the creation of stress concentrations in the frame during operation resultant, in part, from the transfer of loading forces through the crusher.

The object is achieved by specifically positioning and aligning the spider arms at the intermediate flange and topshell. In particular, the inventors have identified that by positioning the spider arms radially inward from an outer circumferential perimeter of the flange that connects the spider to the topshell, the transfer of loading forces between the spider and the topshell is more direct and the need for additional reinforcement ribs below the spider arms is avoided. Accordingly, longitudinal forces are transmitted from the spider arms to the topshell with minimal stress concentrations created in the topshell wall in contrast to conventional reinforced spider and topshell assemblies.

According to a first aspect of the present invention there is provided a gyratory crusher frame part comprising: a topshell mountable upon a bottom shell, the topshell having an annular wall extending around a longitudinal axis of the frame part; a spider having a plurality of arms extending radially outward from a cap positioned at the longitudinal axis, each arm of the plurality of arms having a first portion extending generally in a radially outward direction from the cap and a second portion extending generally in an axial direction from an outer region of the first portion; an annular flange positioned between the second portion of each arm and the annular wall, the flange having an outer circumferential perimeter and an inner circumferential perimeter relative to the longitudinal axis; characterised in that: a radially outermost region of the second portion of each arm is positioned radially inward of the outer circumferential perimeter of the flange.

Preferably, the radially outermost region of the second portion of each arm is positioned radially inward of the outer circumferential perimeter by a distance in the range 5 to 50% of the radial distance between the inner and outer circumferential perimeters of the flange.

Preferably, the radially outermost region of the second portion of each arm is positioned radially inward of the outer circumferential perimeter by a distance in the range 15 to 35% of a radial distance between the inner and outer circumferential perimeters of the flange.

Preferably, the radially outermost region of the second portion of each arm is positioned radially inward of the outer circumferential perimeter by a distance in the range 20 to 30% of a radial distance between the inner and outer circumferential perimeters of the flange.

Preferably, the topshell comprises an outward facing surface and an inward facing surface relative to the longitudinal axis, the annular wall being defined between the outward and inward facing surfaces; wherein a section of the wall neighbouring the flange comprises a concave section at the outer surface and a first half of the concave section in the axial direction closest to the flange is a substantially uniform curve extending continuously in the circumferential direction around the longitudinal axis.

Preferably, the outer surface of the wall at the concave section comprises a curvature extending over the range 170 to 185° in the axial direction.

Preferably, the flange extends directly from one end of the concave section such that one end of the curved outer surface terminates at the outer perimeter of the flange.

Preferably, the first half of the concave section in the axial direction closest to the flange is devoid of any axially extending shoulders that would otherwise interrupt the continuous circumferential curve.

Preferably, a majority of a second half of the concave section in the axial direction comprises a curvature profile substantially equal to a curvature profile of the first half in the axial direction.

Preferably, the outward facing surface at the concave section comprises a curve extending continuously in the axial direction over the first half and the second half.

Preferably, each second portion of each arm comprises a pair of wings that taper outwardly in the axial direction from the first portion to the flange.

Preferably, each wing of the pair of wings is aligned to extend substantially in the circumferential direction with the flange; and wherein a distance in the circumferential direction by which each wing of the pair of wings tapers outwardly is substantially equal to a thickness of the first portion of each arm extending in a plane perpendicular to the longitudinal axis.

Preferably, each wing of the pair of wings is aligned to extend substantially in the circumferential direction with the flange; and wherein a circumferential length or distance by which the second portion extends over the flange substantially in the circumferential direction is greater than a corresponding radial thickness of the second portion in the direction between the inner and outer perimeters.

Preferably, an outward facing part of the second portion of each arm is flared radially outward and an inward facing part of the second portion of each arm is flared radially inward at a region of contact with the annular flange; and wherein the second portion of each arm is flared circumferentially outward such that a cross sectional area of the second portion of each arm increases in the axial direction from the first portion to the flange.

According to a second aspect of the present invention there is provided a gyratory crusher comprising a frame part as claimed in any preceding claim.

DETAILED DESCRIPTION OF ONE EMBODIMENT

The present gyratory crusher and crusher frame assembly comprises those components described with reference to the prior art crusher ofFIG. 1save for the upper frame part101formed from spider110, topshell111and intermediate flange113.

Referring toFIG. 2, the gyratory crusher frame part comprises generally, an annular topshell200mounted upon which is a spider201. Spider201comprises two diametrically opposed arms203that extend radially outward from central cap or mounting boss207positioned centrally about longitudinal axis115extending through upper frame part200, and spider201and generally through the gyratory crusher comprising the bottom shell102, crushing head103and elongate shaft107as described with reference toFIG. 1.

Arms203may be considered to have a radially extending first portion204attached to cap207and a second portion205extending transverse to first portion204in a longitudinal direction corresponding to that of axis115. According to the specific implementation, at least one section of second portion205is aligned perpendicular to first portion204and is aligned substantially parallel to axis115. The first and second portions204,205are formed integrally with a junction between the two portions formed from an arcuate section219being curved towards central axis115.

The second lower portion205and in particular an outward facing surface216represents a radially outermost point, region or surface of each arm203relative to longitudinal axis115. This outermost surface216, according to the specific implementation, is formed by a section of second region205that is aligned parallel to axis115.

Topshell200comprises circumferential walls213defined between an external facing surface209and an internal facing surface214. Internal facing surface214defines, in part, a central chamber212that, in part, defines the crushing zone within which is mounted the crushing head and respective components described with reference toFIG. 1. An annular substantially disc-like flange202extends radially outward from an upper end of topshell wall213. Flange202is defined, in part, by an inner circumferential perimeter224and an outer circumferential perimeter208. An upward facing surface206extends between perimeters224and208and is substantially planar and aligned perpendicular to axis115and orientated to be facing spider201. Flange202is further defined by an opposed downward facing surface220orientated towards topshell200.

Spider201is connected to topshell200via flange202. Lower portion205of each arm203extends in a transverse or perpendicular alignment to planar surface206in a direction of axis115. So as to spread the loading forces transmitted between spider201and topshell200, the second and lower portion205of each arm203comprises a pair or wings223extending either side of lower portion205and in a direction generally following the circumferential path of flange202. Each wing223thereby increases the footprint surface area of each spider arm203and its respective surface area contact with upper planar surface206. In addition to wings223, second portion205(that encompasses wings223) is flared radially outward and radially inward217at respective inward facing surface700and outward facing surface216. Each wing223is additionally flared circumferentially outward218with these flared sections217,218serving to further increase the footprint size of arms203and the surface area contact with surface206. Flared regions217,218comprise a curvature opposite to a curvature of junction219between radial arm portions204and axial arm portions205. Each wing223tapers outwardly in a direction from first portion203to flange upper surface206. Additionally, each wing223flares outwardly at the region of contact with upper surface206both in the radially inward and outward direction217and the circumferential direction218. The second portion205of each arm203comprises a groove215extending axially in the outward facing surface216. Groove215comprises a shape profile suitable to accommodate pipes or other conduits.

Topshell200further comprises a lower flange221axially separated from upper flange202by wall section213. An annular seating collar222is positioned axially below lower flange221and comprises a larger diameter than flanges202,221being suitable for mounting upon bottom shell102via mounting surface210orientated in a downward direction and parallel to upward facing surface206.

Referring toFIGS. 2, 3 and 7, second portion205extends from upper surface206of flange202inward of the outer circumferential perimeter208so as to create a spatial gap300between outer perimeter208and the radially outermost surface216. Accordingly, the majority of the second portion205that extends in the axial direction and upwardly from upper surface206is aligned to be substantially central above upper surface206. Accordingly, a corresponding spatial gap301is created between the inner circumferential perimeter224and radially inward facing surface700. Referring toFIG. 5in particular, the radially outermost region216of each arm203is positioned radially inward of outer perimeter208by a distance501that is substantially 20% to 30% of the radial distance500between the inner224and outer208circumferential perimeters.

FIG. 6illustrates selected relative dimensions of each wing223. In particular, a distance600between first and second edges602,603of first portion204in a plane perpendicular to axis115is substantially equal to a distance601over which each wing223tapers outwardly from first portion204to a region of contact604with upper surface206. As each wing223is aligned along the circumferential path followed by flange202, the wings223extends from second portion205in an angled alignment over surface206. Due to the combined circumferential length of the wings223, a circumferential length or distance by which the arm second portion205extends over the flange surface206substantially in the annular circumferential direction of flange202is greater than a corresponding radial thickness of the arm second portion205in the direction between flange perimeters224and208. This configuration serves to further spread the loading forces in a direction along the circumferential path the flange202.

Referring toFIG. 4, the walls213of topshell200, positioned axially below flange202, comprises a concave profile402at their outer surface209. Curved profile402extends continuously in the axial direction115between underside surface220of flange202and lower flange221. This concave region402may be considered to comprise an upper first half400and a lower second half401relative to axial direction115, with each half400,401separated by bisecting line405shown only for descriptive purposes. The first half400is positioned immediately below flange202and extends from lower surface220.

Similarly, second half401is positioned immediately above lower flange221and extends from an upper surface406of flange221. The first and second halves400,401interface with one another in the axial direction so as to define a substantially uniform curve in which the curve profile, in the axial direction115extends continuously between opposed surfaces220and406.

Four notches211extend radially outward from the outer facing surface of lower half401at discrete regions evenly distributed in a circumferential direction around half401. Notches211define wall sections having a flat base (or cap) and are configured to accommodate anchorage bolts or screws at the internal chamber side212of topshell200.

With the exception of the notch regions211, a curved shape profile404of lower half401is identical to a corresponding curved shape profile403of upper half400. Accordingly, the curvature in the axial direction between surface220and surface406is symmetrical about the central bisecting plane405that extends perpendicular to axis115.

The curve profile403at upper half400, immediately below flange202comprises a substantially uniform curve extending continuously in the circumferential direction around axis115immediately below flange202and in particular downward facing surface220. This endless curve403is devoid of support ribs or shoulders that would otherwise be positioned immediately below each spider arm203and extend axially below surface220according to known topshell and spider assemblies. Accordingly, the continuous, endless or uninterrupted curved profile403transits uniformly any loading forces through topshell200from spider arms203. Accordingly, stress concentrations that would otherwise be created by the axial support shoulders of the known assemblies, is avoided. Furthermore, the present topshell200and spider201assembly is of reduced weight with regard to these known assemblies.

The curve profile403,404that extends in the axial direction between surfaces220and406defines a semi-circular concave region402in which the curve extends over substantially 180° in the axial direction115. As indicated, this curve in interrupted at lower half401by the discrete notch regions211. However, other than regions211, this curve profile403,404is endless, continuous and uniform in the circumferential direction around axis115between flanges202,211. That is, the outward facing surface209between flanges202,211is continuously curved in the axial direction115and is devoid of any axially straight or linear regions.

Referring toFIG. 5, the majority of lower portion205of each arm203is located axially above the concave region402. In particular, curve profile403at upper half400curves radially outward towards surface220such that an appropriate mass of wall213is positioned immediately below the lower portion205of each arm203. Accordingly, loading forces are transmitted through arms203and into the topshell200with such forces being effectively distributed circumferentially around topshell walls213with no or minimal stress concentration creation at the junction between spider201and topshell200. The curve profile404at lower half401further facilitates uniform circumferential distribution of loading forces into the axially lower regions of topshell200and in particular the annular seating collar222.