Title of Invention

A WEAR PLATE ASSEMBLY OF ARMOUR PLATING FOR A ROTARY CRUSHER"

Abstract

A wear plate assembly of armour plating for a rotary crusher consisting of a rotating cylindrical drum intended to rotate around its own longitudinal axis and to contain material to be crushed and a series of crushing devices, the system of armour plating consisting of individual armour plates (10) in rings side by side attached to the inner wall of the drum, each armour plate (10) consisting of a sloping working surface which extends from the bottom (5) to the top (6) of a plate, and a convex attachment surface facing the inner surface of the drum, characterized in that the system contains shoe inserts (11,14) intended to be placed between the individual armour plates (110) and the drum (30) of the crusher, each shoe (11,14) having a main surface whose curve matches the curve of the attachment surface of the adjacent armour plate (10) and an opposite surface whose curve matches that of the drum and that there are two different types of insert shoe (11,14) which are distinguished by the radius of the curve of their main surfaces.

Full Text

This invention concerns a wear plates assembly of armour plating for a rotary crusher consisting of a rotating cylindrical drum intended to revolve around its own longitudinal axis which contains material to be crushed and a series of crushing devices, the armour plating system consisting of individual armour plates arranged in rings placed side by side and fixed on the internal wall of the drum, each armour plate consisting of a sloping working surface stretching from the bottom of the plate to the top of the plate and an opposite convex surface facing the inside surface of the drum. Such a crusher is described in the document EP0998353. This type of crusher is used in particular in cement works and in -the mining industry. The material to be crushed is inserted at one end of the crusher and, as it travels to the outlet at the other end, it is progressively crushed and ground between the crushing devices. In the current situation, the armour plating or protective plates have an attachment area that fits the radius of the curve of the drum and a varying profile depending on how raised one wishes them to be. The fit of the armour plating to the curve of the crusher demands a similar radius of curve for the attachment surface of the plate and the crusher drum so as to avoid breaking the plate and pounding the drum locally. The effect of the desired raising depends on several factors connected to the design of the crusher and the way the latter runs, which means that a specific value of the height that the plates are raised most be determined, and this can vary from 100 mm to 160 mm depending on the circumstances. All this requires the creation of a separate design for the armour plating of each crusher and, as a result, involves a high manufacturing cost and a major capital commitment in terms of stocking spare parts since in general a crushing works sometimes has several crushers of very different dimensions. The aim of this invention is to provide a new armour plating system for a rotary crusher of the type described in the foreword which permits the equipping of crushers of different diameters with metal armour plating of standardised dimensions and with the possibility of adjusting the extent to which they can be raised. To achieve this aim, the armour plating system proposed by this invention is distinguished by the fact that it consists of shoe inserts intended to be fitted between the armour plates and the drum of the crusher, each shoe having a main surface whose curve fits the curve of the attachment surface of the adjacent armour plate and an opposite surface whose curve fits that of the drum. The system has, preferably, at least two types of shoe inserts that are distinguished by the radius of the curve of their main surfaces. At least one of these types has main surfaces which form between them an angle a of less than 10°. The armour plates may be bolted to the drum by means of fixing bolts with half-round heads held in corresponding half-round recesses in the armour plate. Other unusual features and characteristics will emerge from the detailed description of a preferred design presented below, by way of illustration, with reference to the attached drawings, in which: Diagrams la and lb show transversal sections through two different types of armour plating used to date in ball mills; Diagram 2a shows a section across a first type of shoe insert as in this invention; Diagram 2b shows a section across a second type of shoe insert as in this invention; Diagram 3 shows a section across an armour plate equipped with shoes as in Diagram 2a; Diagrams 4a and 4b show a section across an armour plate using the shoes in Diagram 2b in different ways and Diagram 5 shows a section across an armour plate illustrating how it is fixed. Diagrams la and lb show two standard armour plates la and lb. These plates la and lb have a sloping working surface 2 which extends from the bottom of a plate 5 of height h and the top of a plate 3 of height H, as well as a convex attachment surface 4 attached to the internal surface of the drum, which is not represented, and turning, in the case of Diagrams la and lb, in a clockwise direction. This attachment surface 4 could perhaps be made, as represented in the diagrams by broken lines, with perforations to reduce the weight of the plates. Plates la and lb are fixed to the drum by means of bolts, which are not shown. In view of this, plates la and lb have recesses to take the heads of the fixing bolts. The only difference between plates la and lb is that plate la has a working surface which is smooth whereas the working surface of plate lb has longitudinal ridges or other protrusions and hollows of various shapes to reduce the slide of the charge when the crusher is rotating. The attachment surfaces 4 of the two plates must have a curve which more or less matches that of the drum, which has the disadvantages mentioned in the introduction. To resolve this problem, the invention proposes the use of shoe inserts such as those shown in Diagrams 2a and 2b. Diagram 2a shows an example of a thin symmetrical shoe insert 11 made of relatively pure steel which thus allows slight bending, or alternatively made of a type of ductile cast iron with spheroid graphite. This shoe 11 which has the same surface as that of a plate has two main curved surfaces 12 and 13, the top surface 12 having a greater radius of curve than that of surface 13. The shoe 11 has at its centre a hole 16 to take a fixing bolt. Diagram 3 shows an example of the use of shoes 11 for fixing plates 10 of the type in Diagram la to a drum 30 of a crusher. In this case, the curve of the surface 12 of the shoes 11 more or less matches the curve of the attachment surface of the plate 10 whilst the curve of the surface 13 fits the curve of the drum 30. When the plates 10 are fixed to the drum, the shoe will adjust by bending to the diameter and any irregularities of the drum 30 so as to ensure, as shown in Diagram. 3, the best fit for each armour plate 10. Without the presence of these shoes, the plates 10, which have an attachment surface with a larger radius than that of the drum, would not firmly grip the drum in the central section and would soon be bound to break. The shoe 11 in Diagram 2 is symmetrical and only permits the matching of the radii of the curves of the plate and drum without being able to adjust the extent to which the plate 10 that it supports is raised. This shoe will therefore be used when the raising of the plate 10 corresponds to the extent of the raising desired to achieve efficient crushing with the crusher in question. In the case where the raising of the armour plate 10 is too low or too high for the efficient operation of the crusher, the invention proposes a second type of shoe which is illustrated in Diagram 2b. This shoe 14 also has two surfaces 12 and 15 with different curve radii so as to provide a transition between the curve of the plate 10 and that of the drum 30. In any case, here the two surfaces 12 and 15 form an angle a of between 0.1 and 10° and preferably between 1° and 3°. Diagrams 4a and 4b show two different ways of using such a shoe 14. In the configuration in Diagram 4a, the shoe 14 raises the height of the bottom 5 of the plate 10, thus reducing the difference between the height h (see also Diagram la) of the bottom 5 of the plate 10 and the height H of the top 6 of the plate 10, which reduces the effect of raising the crushing load on the crusher. Alternatively, in the configuration in Diagram 4b, the bottom 5 of the plate stays almost at the same level, whereas the top 6 of the plate 10 is raised, which increases the difference between the height h of the bottom of the plate 10 and the height H of the top of the plate, and, be this means, increases the raising effect of the plating. Thus by having available several types of shoe 11 with different curve radii of these surfaces 12 and 13, one could equip crushers of different sizes with the same type of armour plating. Moreover, the extent of the raising can be adjusted as desired not only from one crusher to another but also inside the same drum of a specific crusher. In any case, as can be confirmed by reference to a concrete example below, in practice there is no need for a large number of types of shoes and it is possible to manage with four or even two types of insert shoe. In order to equip crushers with a diameter of between 2.4 and 5.8 metres, a single type of armour plating can be provided with two or four types of insert shoe of which one or two are symmetrical as in Diagram 2a and one or two are as in Diagram 2b. In the case of crushers with a diameter between 2.4 and 3.3 metres, the drum has a small radius of curve, which requires an adjustment of the curve of the attachment surface of the plate to the curve of the drum when the plate is intended for larger crushers. Without this adjustment, there is a risk of breaking the plate since the latter is only supported on its longitudinal edges. Thus a shoe 11 of the type in Diagram 2 will be used which has a surface 12 which matches the curve of the attachment surface of the plate and a surface 13 with a radius of curve between 1.2 metres and 1.6 metres, preferably close to 1.3 m. A shoe 14 can also be provided of the type as in Diagram 2b so as to adjust the extent of the raising, if necessary. In the case of crushers of 3.4 to 5.8 metres, the adjustment of the curves between the bases of the plates 10 and the drum 30 is not so precise because of the size of the radii of the curves. The attachment surface 4 of the single armour plate 10 has itself a curve radius such as allows it to be used with or without a shoe in any type of large crusher depending on the radius of the curve chosen for the attachment surface of the plate 10. In any case, the use of a shoe insert is always recommended so as to avoid problems in operation; either a shoe of type 11 to avoid breakage and pounding of the drum 30 by the plate 10 or a shoe of type 14 to further vary the effect of raising the plating assembly. Thus two shoes are generally used based on the same principle as that described above but with a greater radius of curve of the lower surface 13 or 15 of between 1.7 metres and 2.9 metres, preferably between 1.8 metres and 2.2 metres. In short, the plating system proposed by the invention will be applicable to all crushers of between 2.4 metres and 5.8 metres, by means of the following five parts: - a single armour plate 10 for all crushers; - a symmetrical shoe of type 11 for crushers with a diameter of 2.4 to 3.3 metres; - a shoe of type 14 with an angle of slope a for crushers of 2.4 to 3.3 metres; - a shoe of type 11 for crushers with a diameter of 3.4 to 5.8 metres and - a shoe of type 14 for crushers with a diameter of 3.4 to 5.8 metres. Diagram 5 shows the fixing of the armour plating and the shoes to the drum 30 of a crusher. This fixing is ensured by bolts 22 which go through the plates 10, the shoes 11 or 14 and the drum 30. The use of sloping shoes will require the use of bolts 22 with half-round heads 17 which will be fitted into matching recesses 18 which are also half-round in the plates 10. In this way, whatever the angle that the bottom of the plate 10 forms with the drum 30, the bolt 22 can be correctly tightened without bending the stem of the bolt 22. The convex plating may have the disadvantage of allowing the escape of material through the bolt holes. To alleviate this problem, a washer 19 can be used between the nut and the crusher drum. This washer has a bevelled edge 20 intended to leave a space in which a toroidal gasket 21 made of elastomer can be housed which will be compressed when the bolt is tightened and this will ensure a good seal at the bolt hole. We Claim: 1. A wear plate assembly of armour plating for a rotary crusher consisting of a rotating cylindrical drum intended to rotate around its own longitudinal axis and to contain m.aterial to be crushed and a series of crushing devices, the system of armour plating consisting of individual armour plates (10) placed in rings side by side attached to the inner wall of the drum, each armour plate (10) consisting of a sloping working surface which extends from the bottom (5) to the top (6) of a plate, and a convex attachment surface facing the inner surface of the drum, characterized in that the system contains shoe inserts (11,14) intended to be placed between the individual armour plates (110) and the drum (30) of the crusher, each shoe (11,14) having a main surface whose curve matches the curve of the attachment surface of the adjacent armour plate (10) and an opposite surface whose curve matches that of the drum and that there are two different types of insert shoe (11,14) which are distinguished by the radius of the curve of their main surfaces. 2. A wear plate assembly of armour plating as claimed in claim 1, wherein the two main surfaces (12,15) of each shoe (14) form an angle a between them of less than 10°. 3. A wear plate assembly as claimed in any of the preceding claims, -wherein the plates (10) are bolted to the drum (30) by means of fixing bolts (22) which go through each plate (10), each shoe (11,14) and the drum (30). A wear plate assembly as in claimed in claim 3, wherein the fixing bolts (22) have half-round heads (17) held in matching half-round recesses (18) in the plate (10).

Documents:

751-delnp-2004-abstract.pdf

751-delnp-2004-claims.pdf

751-delnp-2004-complete specification (as files).pdf

751-delnp-2004-complete specification (granted).pdf

751-delnp-2004-correspondence-others.pdf

751-delnp-2004-correspondence-po.pdf

751-delnp-2004-description (complete).pdf

751-delnp-2004-drawings.pdf

751-delnp-2004-form-1.pdf

751-delnp-2004-form-13.pdf

751-delnp-2004-form-19.pdf

751-delnp-2004-form-2.pdf

751-delnp-2004-form-3.pdf

751-delnp-2004-form-5.pdf

751-delnp-2004-gpa.pdf

751-delnp-2004-pct-210.pdf

751-delnp-2004-pct-409.pdf

751-delnp-2004-petition-137.pdf