FRETTING WEAR REDUCTION OF INTERFERENCE FITTED CONE CRUSHER HEAD

Abstract

A cone crusher head, system, and crusher including the cone crusher head and system. A conical mantle radially extends from an interference fit section and has a head diameter D.sub.ch. The conical mantle has a wear part support surface and a shaft support surface. The interference fit section has a nominal interference fit diameter D.sub.if. The conical mantle has an armpit groove for receiving a slip ring. The armpit groove is covered by the conical mantle with an armpit thickness L.sub.a. Fretting wear is reduced by dimensioning the crusher head so that a ratio of the head diameter D.sub.ch to the nominal interference fit diameter D.sub.if is most 2.5; and a ratio of the head diameter D.sub.ch to the armpit thickness L.sub.a is at least 10.5.

Claims

1.-15. (canceled)

16. A crusher head of a cone crusher, comprising: a conical mantle radially extending from an interference fit section, comprising a wear part support surface and a shaft support surface; the shaft support surface comprising the interference fit section for supporting the crusher head to a main shaft; the interference fit section having a nominal interference fit diameter D.sub.if; the conical mantle comprising an armpit groove for receiving a slip ring; the armpit groove being covered by the conical mantle with an armpit thickness L.sub.a that is a minimum distance between a wear part support surface and the armpit; and the conical mantle having a head diameter D.sub.ch that is a maximum diameter of the crusher head; wherein fretting wear is reduced by dimensioning of the crusher head for minimising deformations at the interference fit section by: a ratio of the head diameter D.sub.ch to the nominal interference fit diameter D.sub.if being at most 2.5; and a ratio of the head diameter D.sub.ch to the armpit thickness L.sub.a being at least 10.5.

17. The crusher head of claim 16, wherein the armpit groove is shaped so that both sides are free of constrictions.

18. The crusher head of claim 16, wherein the armpit groove has a rounded top section defined by a first portion of a first circle of a first radius, R.sub.1, and by a second portion of a second circle of a second radius, R.sub.2, wherein the second circle is vertically aligned with the first circle and R.sub.2>R.sub.1.

19. The crusher head of claim 17, wherein the armpit groove has a rounded top section defined by a first portion of a first circle of a first radius, R.sub.1, and by a second portion of a second circle of a second radius, R.sub.2, wherein the second circle is vertically aligned with the first circle and R.sub.2>R.sub.1.

20. The crusher head of claim 18, wherein the first circle extends below the interference fit section.

21. The crusher head of claim 19, wherein the first circle extends below the interference fit section.

22. The crusher head of claim 16, wherein interference fit section has a longitudinal length of at least 50% of the longitudinal length L.sub.ch of the cone crusher head.

23. The crusher head of claim 16, wherein the first portion of the first circle extends on an outer side of the armpit groove at most vertically to a level of the first centre.

24. The crusher head of claim 16, wherein a bottom of the inner side of the armpit groove is aligned with the interference fit section.

25. The crusher head of claim 16, wherein an inner side of the armpit groove approaches a bottom of the interference fit section with a deviation angle from the central axis; and the deviation angle is at most 30 degrees.

26. The crusher head of claim 16, wherein an outer side of the armpit groove meets an intermediate surface with an angle greater than 270 degrees.

27. The crusher head of claim 16, wherein the crusher head is configured to be laterally supported by the main shaft only by the interference fit section.

28. A system comprising the crusher head of claim 16 and the main shaft of a cone crusher, the main shaft comprising an interference fit section for supporting a crusher head, the interference fit section having a nominal interference fit diameter D.sub.if; a bottom shaft section extending between a bottom end of the main shaft and the interference fit section; the bottom shaft section comprising a bottom part and a neck part; wherein the bottom part has a bottom part length L.sub.bp and a bottom part diameter D.sub.bp that is constant below the neck part on at least 50% of the bottom part length L.sub.bp; the neck part has a neck part diameter that is growing towards the interference fit section; and the main shaft has a main shaft length L.sub.ms; wherein for reducing fretting wear in the interference fit section, L.sub.ms.sup.1.3/D.sub.if is at most 40 mm.sup.0.3; and D.sub.bp.sup.1.421/D.sub.if is at most 9.0 mm.sup.0.421.

29. The system of claim 28, wherein the main shaft length L.sub.ms is at least 1200 mm.

30. The system of claim 28, wherein D.sub.bp.sup.1.421/D.sub.if is at most 8.0 mm.sup.0.421.

31. The system of claim 29, wherein D.sub.bp.sup.1.421/D.sub.if is at most 8.0 mm.sup.0.421.

32. The system of claim 28, wherein the main shaft is configured to laterally support the crusher head only by the interference fit section of the main shaft.

33. The system of claim 29, wherein the main shaft is configured to laterally support the crusher head only by the interference fit section of the main shaft.

34. The system of claim 30, wherein the main shaft is configured to laterally support the crusher head only by the interference fit section of the main shaft.

35. A cone crusher comprising the system of claim 28.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0054] Some example embodiments will be described with reference to the accompanying Figures, in which:

[0055] FIG. 1 schematically shows a main shaft of an example embodiment;

[0056] FIG. 2 schematically shows a system of main shaft and a cone crusher head of an example embodiment;

[0057] FIG. 3 schematically shows a cone crusher comprising the system of FIG. 2; and

[0058] FIG. 4 schematically shows some further details of the cone crusher head of FIG. 2.

DETAILED DESCRIPTION

[0059] In the following description, like reference signs denote like elements or steps.

[0060] FIG. 1 schematically shows a main shaft 100 of an example embodiment. FIG. 1 shows some portions and dimensions of the main shaft (ms), such as a thread 110 for attaching a wear part (not shown) by a nut (not shown); an interference fit section 120; a bottom shaft section 130 that comprises a bottom part 134 and a neck part 132 between the bottom part 134 and the interference fit section (120).

[0061] FIG. 1 shows some dimensions such L stands for length, D stands for diameter, and a subscript indicates the object in question.

[0062] In FIG. 1, the bottom part has a constant diameter over its entire length, notwithstanding some possible rounding at the very bottom end. In some other embodiments, the bottom part may have some portions of greater or smaller diameter, but the diameter of the bottom part is present on at least 50% of the length of the bottom part. It is also possible that this at least 50% is formed of two or more portions.

[0063] The interference fit section has a nominal diameter D.sub.if that is configured to fit for cone crusher heads of a shaft opening having the nominal diameter D.sub.if. In an embodiment, one or both ends of the interference fit section have slightly greater nominal diameter, e.g., in the range of tens or hundreds of parts per million in comparison to the nominal diameter D.sub.if.

[0064] As in FIG. 1, the main shaft comprises in an example embodiment only one interference fit section for attaching the crusher head. Preferably, the interference fit section is longitudinally continuous.

[0065] As shown in FIG. 1, the neck part has a neck part diameter that is growing towards the interference fit section. In FIG. 1 embodiment, the neck part grows to the nominal diameter, or in other words, the surface of the main shaft deviates from a perpendicular plane formed with relation to an axial direction of the main shaft, all the way from the centre of the interference fit section 120 over the neck part.

[0066] As also shown in FIGS. 1 and 2, the main shaft 100 can be configured to laterally support or at least to laterally engage with the crusher head only by the interference fit section.

[0067] In the main shaft 100 of FIG. 1, fretting wear is reduced in the interference fit section by forming the interference section and the bottom part such that L.sub.ms.sup.1.3/D.sub.if is at most 40 mm.sup.0.3; while the interference fit section 120 and the bottom part are such that D.sub.bp.sup.1.421/D.sub.if is at most 9.0 mm.sup.0.421.

[0068] It is appreciated that the main shaft 100 and a cone crusher head will form a system. The greater the diameter is at the interference fit section, the wider an opening is required in the crusher head and thus the thinner the structures will be there. It would appear intuitive to assume that since the shaft is squeezed on all sides by the interference fit attached crusher head, the system will become more prone to deformations when the diameter is increased. Surprisingly, though, it was found that in two different commercially available cone crushers, the sliding distance under different loads and fretting wear were reduced in the range of tens percent or even more. While the entire force system is not fully understood, it is believed that the fretting wear can be reduced while L.sub.ms.sup.1.3/D.sub.if is at least 32.0 mm.sup.0.3 or at least 32.5 mm.sup.0.3.

[0069] The second condition, D.sub.bp.sup.1.421/D.sub.if, is expected to operate through dynamics over the bottom part of the main shaft that extend over the interference fit section 120. In an example embodiment, this ratio is at least 6.4 mm.sup.0.421 or at least 6.9 mm.sup.0.421.

[0070] FIG. 2 shows a system 200 of the main shaft 100 and a cone crusher head 210 of an example embodiment. FIG. 2 also shows an inner wear part 220 attached to the cone crusher head 210 by a nut 230. The cone crusher head 210 has a round arm pit groove 240 for receiving a slip ring 320 shown in FIG. 3.

[0071] FIG. 4 illustrates some further details of the cone crusher head 210 of an example embodiment. In particular, FIG. 4 illustrates the dimensions [0072] D.sub.if nominal interference fit diameter; [0073] D.sub.ch head diameter that is a maximum diameter of the crusher head 210; [0074] L.sub.a armpit thickness that is a minimum distance between a wear part support surface and the armpit; [0075] L.sub.ch length or height of the crusher head; [0076] R.sub.1 first radius according to which a first or outer portion of the top of the armpit groove is rounded; and [0077] R.sub.2 second radius according to which a second or inner portion of the top of the armpit groove is rounded.

[0078] In an example embodiment, the cone crusher head 210 comprises the conical mantle 410 radially extending from an interference fit section 420 of the crusher head. The mantle 410 has a wear part support surface or an outer surface and a shaft support surface configured to engage with the interference fit section 120 of the main shaft 100.

[0079] The interference fit section has a nominal interference fit diameter D.sub.if. It shall be appreciated that the nominal diameter of the main shaft 100 and of the corresponding crusher head 210 means slightly differing actual non-stressed diameters in room temperature. Without stress, the main shaft 100 would interference fit section 120 would not quite fit into the interference fit section 420 of the crusher head. Instead, when assembled with suitably heating the cone crusher head and/or cooling the main shaft 100, the assembly will have the interference fit with matching effective diameters on both main shaft and the crusher head 210.

[0080] The armpit groove 240 is covered by the conical mantle 410 with the armpit thickness L.sub.a.

[0081] Fretting wear is reduced by dimensioning the crusher head for minimising deformations at the interference fit section so that [0082] a ratio of the head diameter D.sub.ch to the nominal interference fit diameter D.sub.if is at most 2.5; and [0083] a ratio of the head diameter D.sub.ch to the armpit thickness L.sub.a is least 10.5.

[0084] In an example embodiment, as shown in FIG. 4, the inner radius is continuously decreasing or same from the top of the armpit groove onwards.

[0085] In an example embodiment, as shown in FIG. 4, the outer radius is continuously increasing or same from the top of the armpit groove onwards.

[0086] As mentioned, the armpit groove has a rounded top section, which can be defined by a first portion of a first circle of a first radius, R.sub.1, and by a second portion of a second circle of a second radius, R.sub.2. Advantageously, though not necessarily, the first circle and the second circle have a first centre and second circle that are vertically aligned. In an example embodiment, the second radius is greater than the first radius and/or the second centre resides below the first centre. In an example embodiment, the second centre is perpendicularly aligned with the interference fit section.

[0087] In an example embodiment, the first circle extends below the interference fit section. In an example embodiment, the second circle may extend below the interference fit section. Moreover, in an example embodiment where the rounded top section is defined by a single circle, the single circle may extend below the interference fit section.

[0088] In an example embodiment shown in FIGS. 2 and 3, the first portion of the first circle extends on an outer side of the armpit groove vertically to a level of the first centre. The first portion of the first circle may extend on an outer side of the armpit groove vertically to the level of the first centre.

[0089] In an example embodiment, the first portion of the first circle extends over a sector that extends vertically upwards from the first centre and horizontally outwards from the first centre. The In an example embodiment, the portion of the first circle defines a sector that extends vertically upwards from the first centre and horizontally outwards from the first centre. In an example embodiment, the second portion continues inwards from the first portion. In an example embodiment, the second portion consists of a sector of less than 90 degrees, such as less than or equal to 80 degrees and/or at least 60 degrees.

[0090] In an example embodiment, the inner radius continuously decreases towards the bottom of the interference fit section. In an example embodiment, a bottom of the inner side of the armpit groove is aligned with the interference fit section.

[0091] In an example embodiment, the inner side of the armpit groove approach bottom of the interference fit section with a deviation angle from the central axis, such as at most 40; 30; or 20 degrees; and or at least 30; 20; or 10 degrees.

[0092] In an example embodiment, the outer side of the armpit groove meets an intermediate surface with an angle greater than 270 degrees.

[0093] FIG. 3 schematically shows a cone crusher 300 comprising the system of FIG. 2, comprising the main shaft 100, the cone crusher head 200, an outer wear part 210 and a crushing chamber 320 between the inner and outer wear parts 210, 310.

[0094] Various embodiments have been presented. It should be appreciated that in this document, words comprise; include; and contain are each used as open-ended expressions with no intended exclusivity.

[0095] The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.

[0096] Furthermore, some of the features of the afore-disclosed example embodiments may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.