Roller for grinding machine

Abstract

A tyre for mounting to a grinding roller, the tyre is cylindrical with a profiled ring 22 at each end (fig. 2). The profiled ring comprising a first ring portion with first radial outer surface 26, fi

Description

FIELD OF INVENTION The invention relates to improvements in or relating to rollers which are used in dual roller grinding machines, such as high pressure griding rollers (HPGR). BACKGROUND OF THE INVENTION In HPGR machines, the material to be comminuted is discharged into a gap between two rollers rotating in opposite directions. The material to be comminuted is drawn into the roller gap by the rollers then compacted and crushed. Each roller comprises a central shaft having a radially enlarged central portion (which appears to be cylindrical but actually has a slightly conical shape) on which is mounted a removable tyre. The removable tyre has a large number of blind holes in its outer surface, each of which is populated by a stud protruding from the outer surface of the tyre. The stud is made from a wear resistant material, such as tungsten carbide. Although the studs protect the outer surface of the tyre, the edges of the tyre experience high wear. For this reason, removable end face reinforcements are used at each end of the tyre. The end face reinforcements protect the edges of the rollers from wear. The studs are received in slots which are machined in the edges of the tyre. One type of an end face reinforcement 1 is shown in Fig. 1A which fits into slots in edges of a tyre 2 part of which is shown in Figs. 1B and 1C. End face reinforcement 1 is single piece pre-fabricated body comprising a planar central section 3, a bulb 4 at one end of the planar central section 3 and a pair of wings 5 extending from opposing sides of the planar central section 3. Part of the central section 3 that protrudes below the wings 5 forms a foot or base 6 which has a generally rectangular shape with a rounded inner portion 7. The end face reinforcement 1 is supported on a support surface 8 of the tyre 2. The support surface 8 comprises a series of circumferentially spaced foot supports 9, having a similar shape to the foot or base 6 of the end face reinforcement, and wing spacings 10, with each foot support 9 being adjacent to two wing spacings 10. The foot supports 9 are recessed / lowered relative to the wing supports which supports the foot or base 6 while the wing spacings 10 are arranged to not be in contact with the wings 4 of the end face reinforcement 1. Due to the small portion of the end face reinforcement 1 being supported by the tyre the life expectancy of the end face reinforcement 1 is significantly reduced. It would be advantageous if the support surface of the tyre could be re-designed to reduce the possibility of failure of the end face reinforcement by increasing the portion of the end face reinforcement 1 being supported by the tyre 2. 28 02 25 SUMMARY This summary is provided to introduce a selection of concepts that are further described in the detailed description below. This summary is not intended to identify indispensable features of the claimed subject matter, nor is it intended for use as an aid in limiting the scope of the claimed subject matter. In this application relative terms are used, such as front, rear, up, down, etc., only for ease of the description and understanding of the embodiments, not by way of limitation. Ordinal numbers (first, second, third, etc.) are assigned arbitrarily herein, and are used to differentiate between parts, and do not indicate a particular order, sequence or importance. According to a first aspect there is provided a tyre for mounting around a shaft to provide a grinding roller, the tyre comprising a generally cylindrical body defining a profiled ring at each axial end of the cylindrical body, the profiled ring comprising a first ring portion defining a first radial outer surface and a first axial outer surface, a second ring portion extending axially from the first portion and defining a second radial outer surface having a smaller radius than the first radial outer surface, and a second axial outer surface, a plurality of circumferentially spaced locating recesses extending radially inwards from the first radial outer surface and defining an opening in the first axial outer surface for receiving at least a portion of a peripheral wear member; and a plurality of circumferentially spaced support recesses extending from the locating recesses radially inwards, each recess having a central section extending axially inward from the second outer axial surface and a pair of wing support portions which extend laterally from opposed sides of the central section through a portion of the second ring portion adjacent to the central section, a radial inner surface of each recess defining a foot support surface which is recessed relative to the second outer radial surface. Each support recess may further comprise a bulbous portion extending around an inner portion of the central section. The central section of each support recess may extend axially inward from the second outer axial surface and be positioned adjacent to two wings arrangements defined by the second radial outer surface. Each support recess may further comprise a pair of wing support portions which extend laterally from opposed sides of the central section through a portion of the second ring portion adjacent to the central section. The wing support portions may extend from the second axial outer surface axially inwards towards the first axial outer surface. The wing support portions may define a radial inner surface which defines wing support surfaces which are recessed relative to the second radial outer surface. The wing support surfaces and the foot support surface may be merged and form a substantially planar support 28 02 25 surface. Alternatively, the wing support surface may be recessed or raised relative to the foot support surface. The wing support portions of adjacent support recesses may be separated by a raised section of the second ring portion which is raised relative to the wing support surface. Alternatively, the wing support portions of adjacent support recessed may extend through the second ring portion so that adjacent wing support portions are merged. Each support recess may further comprise a pair of transition portions which extend from the wing supports towards the bulbous portion with an inner radial surface of the transition portion forming part of the foot support. The bulbous portion may further define a neck transverse to an axial direction at an outer part of the bulb portion, the bulb portion further comprising a pair of first curved portions at an axial inner part thereof, and a pair of second curved portions adjacent to the neck. The first curved portions may have the same shape, for example, the same radius. Alternatively, the first curved portions may have a different shape, for example, different radii. Each curved portion may not have a single radius. The first and second curved portions may be connected, or separated, by a third portion, such as a planar portion or another curved portion. The bulb portion may comprise a curved rear surface or rear surface portion with one end of each of the first curved portions connected to one another. Alternatively, or additionally, the bulb portion may comprise a generally flat rear surface or rear surface portion with one end of each of the first curved portions connected to a central planar portion. Each locating recess includes an inner bulb portion and a pair of transition portions extending from the inner bulb portion towards the first axial outer surface. Each non-planar transition region may comprise a transition surface which comprises a curved surface; a plurality of curved surfaces; a polygon surface, a surface comprising one or more planar portions and curved portions; or the like. Where the transition surface comprises one or more planar portions and curved portions it may comprise a planar portion extending at an acute angle to the central axis and an arcuate surface at each end thereof, wherein one arcuate surface is adjacent to, and merges with, the neck of the bulb portion, and the other arcuate surface is adjacent to, and merges with, a respective wing. Each non-planar transition region may comprise a transition surface in the form of a curve having a radius between 7mm and 12mm, in some embodiments approximately 9mm. 28 02 25 The inner bulb portion may comprise an inner central section and a pair of side surfaces extending axially from the central section towards the first axial outer surface with each side surface comprising a concave portion and a convex portion. The bulb portion may comprise a pair of first curved portions at a rear thereof, and a pair of second curved portions adjacent to the neck on opposed sides of locating recess. The first curved portions may have the same shape, for example, the same radius. Alternatively, the first curved portions may have a different shape, for example, different radii. Each curved portion may not have a single radius. The first and second curved portions may be connected, or separated, by a third portion, such as a planar portion or another curved portion. The bulb portion may comprise a curved rear surface or rear surface portion with one end of each of the first curved portions connected to one another. Alternatively, or additionally, the bulb portion may comprise a generally flat rear surface or rear surface portion with one end of each of the first curved portions connected to a central planar portion. The wing support portions of adjacent supporting recesses may be separated by a portion of the second ring portion. The foot support surface may be recessed relative to the second radial outer surface. Alternatively, the wing support portions of adjacent supporting recesses may merge with one another. The second radial outer surface may then be defined by the portion of the foot support surface extending axially from the first portion of each circumferentially spaced locating recess. According to a second aspect there is provided a grinding roller comprising a tyre of the first aspect further comprising a bore extending axially through the tyre and a shaft on which the tyre is mounted. According to a third aspect there is provided a grinding roller comprising a tyre of the first aspect and a plurality of peripheral wear members mounted around a periphery of each axially spaced end of the tyre to form a generally continuous reinforcement edge for resisting axial and radial wear thereof. The grinding roller may comprise a bore extending axially through the tyre. The bore may be configured to allow the tyre to be concentrically mounted onto a shaft. Alternatively, the tyre and the shaft may be of unitary contruction. According to a sixth aspect there is provided a high pressure grinding roller machine comprising a pair of grinding rollers of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1A is a perspective view of a prior art peripheral wear member; Figs. 1B and 10 are perspective views of a portion of a prior art tyre for mounting around a shaft to provide a grinding roller; 28 02 25 Fig. 2 is a schematic perspective view of a tyre including a profiled ring at each end, populated with a plurality of circumferentially adjacent peripheral wear members; and Fig. 3 is a detailed perspective view of a profiled peripheral end of a roller according to a first embodiment of the invention; Fig. 4A is a top view of part of the profiled peripheral end of a roller of Fig. 3; Fig. 4B is a perspective view of part of the profiled peripheral end of a roller of Fig. 3 ; Figs. 5 to 6 are detailed perspectives views showing two different stages in which a peripheral wear member of Fig. 13is inserted into one of the recesses in the profiled end of a roller of Fig. 3; Fig. 7 is a detailed perspective view of a profiled peripheral end of a roller according to a second embodiment of the invention; Figs. 8 to 9 are detailed perspectives views showing two different stages in which a peripheral wear member of Fig. 14 is inserted into one of the recesses in the profiled end of the roller of Fig. 7; Fig. 10 is a detailed perspective view of a profiled peripheral end of a roller according to a third embodiment of the invention; Figs. 11 to 12 are detailed perspectives views showing two different stages in which a peripheral wear member of Fig. 15 is inserted into one of the recesses in the profiled end of the roller of Fig. 10; Fig. 13 is an underside perspective view of a peripheral wear member for use with the roller of Fig. 3; Fig. 14 is an underside perspective view of a peripheral wear member for use with the roller of Fig. 7; and Fig. 15 is an underside perspective view of a peripheral wear member for use with the roller of Fig. 10. DETAILED DESCRIPTION OF EMBODIMENTS A grinding roller tyre 12 for a High Pressure Griding Roller (HPGR) is schematically illustrated in Fig. 2 in perspective view from one axial end 14a thereof. The second axial end 14b is identical to the first end 14a, so will not be described. The grinding roller tyre 12 is generally cylindrical and includes an arcuate outer surface 16 populated with tungsten carbide studs (not shown for clarity) protruding therefrom, and terminating at each axial end 14a, 14b. Typically, the grinding roller tyre (approximately 100mm thick although the grinding roller tyre may be radially segemnted) includes an internal machined surface 18 defining a frusto-conical bore extending the axial length (direction 20) of the tyre 12. The angle of slope of the frusto-conical bore is very small (typically less than four degrees). The machined surface 18 mounts on a HPGR shaft (not shown) as an interference fit. The grinding roller tyre 12 further comprises a profiled ring portion 22 at each axial end (only one of which is shown in Figs. 3 to 5 but the other end is identical other than being a mirror image thereof). It is to be appreacted that the profiled ring portion 22 may consist of a plurality of segmented portions. Reference is now made to Figs. 3, 5 and 6 which are detailed perspective views of a profiled ring 22 and Figs. 4A and 4B which are a top view and a perspective view of part of the profile ring 22 according to a first embodiment of the invention. The profiled ring 22 comprises a first ring portion 24 which defines a first radial outer surface 26 which is raised by a small amount (a few mm) relative of most of the tyre outer surface 16 and a first axial outer surface 28. The profiled ring 22 also comprises a second ring portion 30 which extends axially (direction 20) from the first ring portion 22 and defines a second radial outer surface 32, which has a smaller radius than the first radial outer surface 28 and a second axial outer surface 34. The profiled ring 22 further comprises a plurality of circumferentially spaced locating recesses 36 with each locating recess 36 extending radially inwards from the first radial outer surface 26 and axially inwards from the first axial outer surface 28. Each locating recess 36 includes an inner bulb portion 38 located axially inward from the first axial outer surface 28 and which extends the length of the locating recess 36. The inner bulb portion 38 comprises an inner central section 40 (which is generally planar) and a pair of side surfaces 42 extending axially from the inner central section 40 towards the first axial outer surface. In this embodiment, the inner bulb portion 38 is symmetrical about a centreplane 44 (best seen in Fig. 3) but in other embodiment, the inner bulb portion 38 may be asymmetrical. In this embodiment, each side surface 42 comprises a convex portion 46 adjacent to the inner central section 40, a generally planar portion 48 and a concave portion 50. In an alternative embodiment, the inner central section 40 may not be used, i.e. the side surfaces 42 are adjacent one another. In further alternative embodiments, the planar portion 48 may not be used, i.e. the convex portion 46 may blend into the concave portion 50. The inner bulb portion 38 further defines a neck 51 which is transverse to centreplane (or in other words transverse to the axial axis 53)(best seen in Fig. 4A) at an outer part of the inner bulb portion 38. The bulb portion 38 narrows (in the circumferential direction) to the neck 51 at its furthest outer part so that the neck 51 is adjacent and merges with the concave portions 50. Each locating recess 36 further includes a pair of transition portions 52 which extend from the concave portion 50 at the neck 51 of the inner bulb portion 38 towards the first axial outer surface 28. The transition portions 52 defines an arcuate transition surface, which in this embodiment is generally concave. The transition portions 52 of adjacent locating recesses are separated by an portion 54 of the first axial outer surface 38. In this embodiment, the concave portions 50 has a radius (R1) larger than the transition surface radius (R2). In particular, in this embodiment, the concave portions 50 have a radius (R1) of approximately 10mm or 12mm (plus or minus 10%); whereas the transition surface 52 has a radius (R2) of approximately 9mm or 11mm (plus or minus 10%). The locating recesses 36 are shaped and dimensioned to receive at least part of a peripheral wear member 300 as shown in Fig. 13. In this embodiment, each locating recess may extend approximately 30-70mm radially inwards from the first radial outer surface 26. In this embodiment, each locating recess 36 extends radially inwards from the first radial outer surface 26 with a radial inner portion of each locating recess 36 radially above the second radial outer surface 32. The profiled ring 22 further includes a plurality of circumferentially spaced support recesses 56 which extend from the locating recesses 36 radially inwards (direction 58) so that the locating recesses 36 and support recesses 56 are circumferentially aligned. Each support recess 56 comprises a central section 60 which extends axially inward (direction 20) from the second axial outer surface 34 . The central section 60 is defined: circumferentially by the portion between CSC1 and CSC2 (see Fig. 4A) and axially by the portion between the second axial outer surface 34 / CSA1 and CSA2 (see Fig. 4A). It will be appreciated that this definition is primarily to aid clarity and understanding, the boundaries of the central section 60 could be moved to some extent. In this embodiment, the central section 60 includes a curved inner surface 61. Each support recess 56 includes a pair of wing supports 62 extending laterally from opposed sides of an outer portion of the central section 60 through a portion of the second outer radial surface 32 on opposed sides of the central section 60. A radial inner surface 64 of each support recess (central section 60 and wing supports 62) defines a foot support surface 64 which is recessed relative to the second outer radial surface 32. In this embodiment the wing supports 62 of adjacent support recesses 60 are separated by a portion of the second outer radial surface 32. In other configurations wing supports of adjacent support recesses may merge with one another. In such a configuration the foot support surface of each support recess may be recessed relative to the locating recess. The second radial outer surface is then defined by the radial inner surface 64 of the circumferentially spaced support recesses. The radial inner surface 64 of each support recess may be substantially planar such that the second radial outer surface is substantially polygon shaped. In this embodiment, the wing supports 62 each comprises a generally planar portion 66 extending from the second axial outer surface 34 axially inwards and an arcuate portion 68 extending from the generally planar portion 66 axially inwards. Each support recess 56 further includes a pair of transition surfaces 70 each having an arcuate portion which extend from the central section 60 towards the arcuate portion 68 of each of the wing supports 62. The transition surfaces 70 may each comprise curved surface; a polygon surface, a surface comprising one or more planar portions and curved portions. In this embodiment, the transition surfaces each comprise a curved surface, more specifically, a concave surface. In an alternative embodiment the transition surfaces 70 include an arcuate portion adjacent to the arcuate portion 68 of the wing supports 62 and a generally planar portion adjacent to central section 60. The support recess 56 (in this embodiment the central section 60 and a portion of the wing supports 62) extends through the first axial outer surface 28 so that a radial inner portion of the locating recess 36 (more specifically the central section 60) merges with a radial outer portion of the support recess 56. The lower portion of the locating recess 36 may define a chamfer portion 71 between the support recess 56 and the locating recess 36 on all sides of the locating recess. The support recess 56 defines a chamfer portion 72 on all sides of the foot support surface 64 extending to the surrounding periphery of the support recess defined by the central section 60, wing supports 62 and transition surfaces 70. The first portion 24 of the profiled ring 22 has a generally tongue and groove appearance with the locating recesses 36 defining the grooves and alternating with protruding tongues (the portion of the first ring portion between adjacent locating recesses which is defined by the transition surface 52 of adjacent locating recesses 36 and portion 54 of first axial outer surface). The combination of a locating recess 36 and half (on a circumferential basis) of each adjacent tongue provide a wear member locating feature. The wear locating feature allows a wear member 300 having a bulb portion 302 which is complementary to inner bulb portion 38 to be inserted into the locating recess 36. Half of each adjacent tongue (the concave portion 50 of the inner bulb portion 38 at the neck 51) encloses a neck 304 of a wear member 300 therebetween to prevent the wear member 300 from moving axially out of the profiled ring 22. With the wear member 300 inserted into the locating recess 36 a lower portion or base 306 (which includes the central section 310 and wings 312) of the wear member 300 is received within the support recess 56 with a lower surface of foot 308 of base 306 (both central section and wings 312) are supported by the foot support surface 64 defined by the inner radial surface of the central section 60 and the wing supports 62. The profile ring 22 therefore provides improved stability to the wear member 300 as the foot support surface 64 is increased relative to the prior art. Furthermore, the top wear part (upper surface 311) adjacent wings 316 of the peripheral wear member 300 is supported in height to minimize the stress in the peripheral wear member 300 (caused by crushing forces) to prevent chipping and breaking of the peripheral wear member 300. Once all of the peripheral wear members 300 have been inserted, the profiled ring 22 is fully populated (as shown in Fig. 6), thereby providing high wear resistance in both the radial and axial directions at each end of the grinding roller. As best seen in Figs. 7-9 a second embodiment of a profiled ring 122 of a tyre 112 is shown having a different support recesses 156 and support surfaces or foot support surfaces 164 to that of the profiled ring 22 while the features of the locating recess 136 remain similar. The support recesses 156 each includes a central section 160 and a bulbous portion 174 extending around an axial inner portion of the central section 160. A radial inner surface 164 of each support recess defines a foot support surface which is recessed relative to the second outer radial surface 132. The central section 160 is defined: circumferentially by the portion between CSC1 and CSC2 (see Fig. 7) and axially by the portion between the second axial outer surface 134 and CSA1 (see Fig. 7). It will be appreciated that this definition is primarily to aid clarity and understanding, the boundaries of the central section 60 could be moved to some extent. The bulbous portion 174 corresponds to the inner bulb portion 138 of the locating recess 136. In this embodiment, the bulbous portion 174 has an outer periphery which is smaller than the outer periphery of the inner bulb portion 136. The support recess 156 (in this embodiment the central section 160) extends through the first axial outer surface 128 so that a radial inner portion of the locating recess 136 merges with a radial outer portion of the support recess 156. The lower portion of the locating recess 136 may define a chamfer portion 171 between the support recess 156 and the locating recess 136 on all sides of the locating recess. In this embodiment, the bulbous portion 174 includes a central surface 176 which is generally planar, and a pair of curved side portions 178 (on each side of the central portion) having an arcuate shape. In an alternative embodiment, the central section 176 may not be used, i.e. the curved side surfaces 178 are adjacent one another. In this embodiment, the bulbous portion 174 is symmetrical about a centreplane 144 (best seen in Fig. 7) but in other embodiment, the bulbous portion 174 may be asymmetrical. In this embodiment, each curved side portion 178 comprises a convex portion 180 adjacent to the inner central surface 176, a generally planar portion (not shown) and a concave portion (not shown) that merges with the central section 160 at a neck 182. However in other embodiments, the planar portion may not be used, i.e. the convex portion 180 may blend into the concave portion . The neck 182 is transverse to centreplane 144 at an outer part of the bulbous portion 174 (as shown in Fig. 7). The bulbous portion 174 narrows (in the circumferential direction) to the neck 182 at its furthest outer part so that the neck 182 is adjacent and merges with the concave portions (not shown). The central section 160 of each support recess 156 is adjacent to two wing arrangements 184 (and vise versa) defined by the second outer radial surface 32. The foot support surface 164 of each support recess 156 is recessed relative to the wing arrangements 184 (and subsequently the second outer radial surface 132) by a predetermined distance. With the wear member 400 (as shown in Fig. 14) inserted into the locating recess 136 a lower portion or base4 406 of the wear member 400 is received within the support recess 156 with a lower surface or foot 408 of the wear member 400 supported by the foot support surface 164. The concave portions on opposing sides of the central section 160 at the neck 182of the bulbous portion 174 encloses a neck 414 of the bulbous portion 415 of the base 406 therebetween to provide additional support to the wear member 400 to also prevent the wear member 400 from moving axially out of the profiled ring 122 as opposed to current designs where the support recess is a substantially rectangular surface with cannot enclose the neck 414 of the base 406. This has the advantage that stress in the region of the neck 151 of the bulb portion 148 caused by crushing forces is reduced by restricting axial movement of the peripheral wear member 400 due to the bulbous portion 415 of the base 406 being held in position by the tyre over the total radial heigh of the bulbous portion 415. By reducing the stress in the region of the neck 151 deformation thereof is prevented which prevents dislocation of the peripheral wear member 400 from the tyre. The peripheral wear member 400 further includes wings 416 which extends laterally from an outer portion of the wear member 400. With the wear member 400 inserted into the locating 136 and support recesses 156, the wings 416 of the wear member 400 sit above the wings arrangements 184. Once all of the peripheral wear members 400 have been inserted, the profiled ring 122 is fully populated (as shown in Fig. 9), thereby providing high wear resistance in both the radial and axial directions at each end of the grinding roller. As best seen in Figs. 10-12 a third embodiment of a profiled ring 222 of a tyre 212 is shown having a different support recesses 256 and support surface or foot support surfaces 264 to that of the profiled ring 22 and 122 while the other features remain similar. The support recesses 256 each includes a central section 260,a bulbous portion 274 extending around an inner part of the central section 260 as with the profiled ring 122, and a pair of wings supports 262 extending laterally from an outer part of the central section 260 as with the profiled ring 22. The central section 260 is defined: circumferentially by the portion between CSC1 and CSC2 (see Fig. 10) and axially by the portion between the second axial outer surface 234 and CSA1 (see Fig. 10). It will be appreciated that this definition is primarily to aid clarity and understanding, the boundaries of the central section 260 could be moved to some extent. The bulbous portion 274 corresponds to the inner bulb portion 238 of the locating recess 236. In this embodiment, the bulbous portion 274 has an outer periphery which is smaller than the outer periphery of the inner bulb portion 236. In this embodiment, the bulbous portion 274 includes a central surface 276 which is generally planar, and a pair of curved side portions 278 (on each side of the central portion) having an arcuate shape. In an alternative embodiment, the central section 276 may not be used, i.e. the curved side surfaces 278 are adjacent one another. In this embodiment, the bulbous portion 274 is symmetrical about a centreplane 244 (best seen in Fig. 10) but in other embodiment, the bulbous portion 274 may be asymmetrical. In this embodiment, each curved side portion 278 comprises a convex portion 280 adjacent to the inner central surface 276, a generally planar portion (not shown) and a concave portion (not shown) that merges with the central section 260 at a neck 282. However in other embodiments, the planar portion may not be used, i.e. the convex portion 280 may blend into the concave portion . The pair of wing supports 262 extends laterally from opposed sides of an outer portion of the central portion 260 through a portion of the second outer radial surface 232 on opposed sides of the central portion 260. Wing supports 262 of adjacent support recesses 260 are separated by a portion of the second outer radial surface 232. In other configurations wing supports of adjacent support recesses may merge with one another. In such a configuration the foot support surface of each support recess may be recessed relative to the locating recess. The second radial outer surface is then defined by the radial inner surface 64 (the portion of the support recess in the second ring portion) of the circumferentially spaced support recesses. The radial inner surface 64 of each support recess may be substantially planar such that the second radial outer surface is substantially polygon shaped. In this embodiment, the wing supports 262 each comprises a generally planar portion (not shown) extending from the second axial outer surface 234 axially inwards and an arcuate portion 268 extending from the generally planar portion inwards. Each support recess 256 further includes a pair of transition surfaces 270 which extend from the bulbous portion 274 towards each of the wing supports 262. The transition surfaces 270 may each comprise curved surface; a polygon surface, a surface comprising one or more planar portions and curved portions. In this embodiment, the transition surfaces each comprise a curved surface, more specifically, a concave surface. In an alternative embodiment the transition surfaces 270 include an arcuate portion adjacent to the arcuate portion of the wing supports and a generally planar portion adjacent to the bulb portion. With the wear member 500 (as shown in Fig. 15) inserted into the locating recess 236 a lower portion or base 506 of the wear member 500 is received within the support recess 256 with a lower surface of foot 508 of the wear member 500 supported by the foot support surface 264. The concave portion on opposing sides of the central section 260 at the neck 282 of the bulbous portion 274 encloses a neck 514 of the base 506 therebetween to provide additional support to the wear member 500 to further prevent the wear member 500 from moving axially out of the profiled ring 222 as opposed to current designs where the support recess is a substantially rectangular surface with cannot enclose the neck 514 of the base 506. The profile ring 222 further provides improved stability to the wear member 500 as the foot support surface 264 is increased relative to the prior art. The increased foot support surface 264 allows not only the central section of the base 506 to be supported but wings 512 of the base 506 of the wear member 500. An alternative description of the supporting recess 56, 156, 256 a different way of describing the same shape) is that each supporting recess has a central section extending axially inward from the second outer axial surface and an auxiliary section extending from the central section laterally beyond the neck of the locating recess, a radial inner surface of each supporting recess (central section and auxiliary section) defining a foot support surface which is recessed relative to the locating recesses. The auxiliary section may be defined by a pair of wing support portions extending laterally from an outer portion of the central section as shown in Figs. 3-5, a bulbous portion extending around an inner portion of the central section as shown in Figs. 7-8, or both a pair of wing support portions and a bulbous portion as shown in Figs. 10-11.In the foregoing description of certain embodiments, specific terminology has been used for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "upper" and "lower", "above" and "below" and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms, nor to imply a required orientation of the wear member. The word “or” is used to indicate that one or more of the words listed may be present, unless the context requires the disjunctive use. In this specification, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of’. A corresponding meaning is to be attributed to the corresponding words “comprise", "comprised" and "comprises" where they appear. The preceding description is provided in relation to several embodiments which may share common characteristics and features. It is to be understood that one or more features of any one embodiment may be combined with one or more features of the other embodiments. In addition, any single feature or combination of features in any of the embodiments may constitute additional embodiments. In addition, the foregoing describes only some embodiments of the inventions, and alterations, modifications, additions and / or changes can be made thereto without departing from the scope of the disclosed embodiments, the embodiments being illustrative and not restrictive. List of reference numerals: End face reinforcement 1 Tyre 2 Planar central section 3 Bulb 4 Pair of wings 5 Foot or base 6 Rounder inner portion 7 Support surface of tyre 8 Foot support 9 Wings spacings 10 Grinding roller tyre 12, 112 Axial ends (of tyre) 14a, 14b Outer surface (of tyre) 16, 116 Internal machined surface (of tyre) 18 Axial direction 20 Profiled ring (of tyre) 22, 122, 222 First ring portion 24, 124, 224 First radial outer surface 26, 126, 226 First axial outer surface 28, 128, 228 Second ring portion 30, 130, 230 Second radial outer surface 32, 132, 232 Second axial outer surface 34, 134, 234 Locating recesses 36, 136, 236 Inner bulb portion (of locating recess) 38, 138, 238 Inner central section (of bulb portion) 40, 140, 240 Side surface 42, 142, 242 Centreplane 44, 144, 244 Convex portion (of bulb portion) 46, 146, 246 Planar portion (of bulb portion) 48 Concave portion (of bulb portion) 50 Neck (of bulb portion) 51, 151,251 Transition portions (of locating recess) 52, 152, 252 Portion of first axial outer surface 54, 154, 254 Support recesses 56, 156, 256 Radial direction 58 Central section (of support recess) 60, 160, 260 Curved inner surface (of central section) 61 Wing support (of support recess) 62, 262 Radial inner surface / Foot support surface 64, 164, 264 Planar portion (of wing support) 66 Arcuate portion (of wing support) 68, 268 Transition surfaces 70 Chamfer portion (between support recess and locating recess) 71, 171, 271 Chamfer portion (between foot support surface and support recess) 72, 272 ,272 Bulbous portion (of support recess) 174, 274 Central surface (of bulbous portion) 176, 276 Curved portions 178, 278 Convex portion (of bulbous portion) 180, 280 Neck (of bulbous portion) 182, 282 Wings arrangements 184 Peripheral wear member 300, 400, 500 Bulb portion (of peripheral wear member)302, 402, 502 Neck (of bulb portion) 304, 404, 504 Lower portion or base (of peripheral wear member) 306, 406, 506 Lower surface or foot (of peripheral wear member) 308, 408, 508 Central section (of base) 310, 410, 510 Upper surface of wear member 311, 411, 511 Wings (of base) 312, 512 Wings (of peripheral wear member) 316, 416, 516 Neck (of base) 414, 514 Bulbous portion (of base) 415, 515 28 02 25

Claims

1. A tyre for mounting around a shaft to provide a grinding roller, the tyre comprising:a generally cylindrical body defining a profiled ring at each axial end of the cylindrical body, the profiled ring comprising:a first ring portion defining a first radial outer surface and a first axial outer surface,a second ring portion extending axially from the first portion and defining a second radial outer surface having a smaller radius than the first radial outer surface, and a second axial outer surface,a plurality of circumferentially spaced locating recesses extending radially inwards from the first radial outer surface and defining an opening in the first axial outer surface for receiving at least a portion of a peripheral wear member; anda plurality of circumferentially spaced support recesses extending from the locating recesses radially inwards, each recess having a central section extending axially inward from the second outer axial surface and a pair of wing supports which extend laterally from opposed sides of the central section through a portion of the second ring portion adjacent to the central section, a radial inner surface of each recess defining a foot support surface.

2. A tyre according to claim 1, wherein the foot support surface of each support recess is recessed relative to the second outer radial surface with wing supports of adjacent support recesses separated by a raised section of the second ring portion.

3. A tyre according to claim 1, wherein adjacent wing supports merge with one another so that the radial inner surface of the support recesses define the second radial outer surface with the second radial outer surface having a substantially polygon shape.

4. A tyre according to any preceding claim, wherein each support recess further comprises a pair of transition portions which extend from the wing supports towards the central section with an inner radial surface of the transition portion forming part of the foot support.

5. A tyre according to any preceding claim, wherein each support recess further comprises a bulb portion extending around an inner portion of the central section.

6. A tyre according to claim 5, wherein the bulb portion defines a neck transverse to an axial direction at an outer part of the bulb portion, the bulb portion further comprising a pair of first curved portions at an axial inner part thereof, and a pair of second curved portions adjacent the neck.28 02 257. A tyre according to any preceding claim, wherein each locating recess includes an inner bulb portion and a pair of transition portions extending from the inner bulb portion towards the first axial outer surface.

8. A tyre according to claim 7, wherein the inner bulb portion comprises an inner central section and a pair of side surfaces extending axially from the central section towards the first axial outer surface with each side surface comprising a concave portion and a convex portion.

9. A grinding roller comprising a tyre according to any preceding claim further comprising a bore extending axially through the tyre and a shaft on which the tyre is mounted.

10. A grinding roller comprising a tyre according to any preceding claim and a plurality of peripheral wear members mounted around a periphery of each axially spaced end of the tyre to form a generally continuous reinforcement edge for resisting axial and radial wear thereof.

11. A high pressure grinding roller machine comprising a pair of grinding rollers according to claim 10.

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