Crushing apparatus

Abstract: This invention relates to a crushing apparatus which is suitable for use in conjunction with boring and tunnelling equipment. One form of crushing apparatus (See Figure 2) comprises an inner member (10) and an outer member (20) mounted coaxially for relative rotation about axis X - X. A crushing chamber (21) is of generally annular shape and converges from an inlet (22) towards an outlet (23). The peripheral walls of the crushing chamber (21) are constituted by faces (24), (25) respectively the inner (10) and outer (20) members which are of multi-face right-conical form. The number of faces on the inner (10) and outer (20) members differ by at least one. Embodiments of crushing apparatus where the number of faces on the inner (10) and outer (20) members differ in number by two or three are specifically disclosed and possess the advantage that, during use, balance of the relatively rotating parts of the crushing apparatus is readily achieved.

Description: This invention relates to a crushing apparatus for crushing and thereby breaking down rock and other material into pieces of smaller size than that originally fed into the apparatus. A crushing apparatus in accordance with the present invention is suitable for use in conjunction with boring and tunnelling equipment as well as crushing quarried material. The crushing apparatus in accordance with the invention can be used in conjunction with both large and small scale boring/tunnelling equipment such as macro-tunnelling equipment for producing tunnels suitable for vehicular transportation and micro-tunnelling equipment for producing tunnels suitable for man-entry. CH-A-344285 discloses a crusher for crushing rocks comprising a casing (1) having a through bore of octagonal cross section and a concentrically mounted rotor (3). Essentially the rotor (3) is a frusto-right circular cone having four flat faces (4) which are generally semi-illiptical in shape. Thus, since the four faces (4) are of equal transverse width, the top of the rotor (3) is square, whereas the base of the rotor (3) is circular as shown in figure 3. DE-3911378A1 describes a crusher comprising an outer stationary frusto-conical cutting sleeve (8) having a frusto-conical surface (19) and an internal cone crusher (17) which is mounted for rotation about an axis which is eccentric relative to the sleeve (8). The internal cone crusher (17) is also formed with longitudinal crusher ribs (41) and concentric circular crushing rings (42). When compared with the crushers disclosed in CH-A-344285 and DE-A-3911378 the crushing surfaces in the crusher of the present application are continuous over the full length of the crushing chamber and they extend downstream through the actual outlet so as to clear or extend beyond convergent parts of the cone crusher. According to the present invention a crushing apparatus comprises a crushing apparatus comprising a generally annual crushing chamber (21) having an inlet (22) for receiving material to be crushed and outlet (23) through which crushed material is discharged, the annular crushing chamber comprising coaxially mounted inner (10) and outer members (20), each member having a frusto-conical peripheral wall which converge towards the outlet with each peripheral wall having a different number of faces (24, 25) and means for creating relative angular movement between the inner (10) and outer (20) members whereby material introduced into the crushing chamber through the inlet (22) is crushed between the peripheral walls during relative rotation thereof and passage from the inlet (22) to the outlet (23), characterised in that the faces (24, 25) of each peripheral wall extend from the inlet (22) to the outlet (23) of the crushing chamber (21) whereby the outlet (23) is annular and is defined by inner and outer peripheral walls having a number of faces corresponding to the number of faces (24,25) of the peripheral walls of the inner (10) and outer (20) members, in that the inner member (10) includes an extension (10A) located within the outlet (23) and in that the extension (10A) has a peripheral wall having the same number of faces (24) as the inner member (10). According to one embodiment of a crushing apparatus and when considered in coaxial cross-section, the peripheral wall of the frusto-conical inner member (10) diverges outwardly towards the outlet (23) and the peripheral wall of the frusto-conical outer member converges inwardly towards the outlet (23) whereby the annular extent of the crushing chamber is progressively reduced from the inlet to the outlet. In this embodiment one end of the inner member (10) is located in the region of the inlet (22) and includes at least two equi-angularly disposed arms (26) extending radially outwardly from the inner member (10). The inner member (10) is conveniently supported on a shaft (33) which is mounted coaxially within a bore (20A) formed in the outer member (20) and rotatable therein. In order further to reduce the size of crushed material after passage through the outlet, an appropriate clearance exists between the shaft (33) and bore (20A) forming a secondary crushing chamber (28), in which the shaft and the bore are fitted with axially displaced and inter-digitated prongs (29,30) for effecting secondary crushing of the material. The crushing apparatus according to the invention may be used in conjunction with tunnelling equipment and positioned to the rear of the tunnelling equipment so that material removed during tunnelling is immediately crushed into a required size thereby easing removal and transportation of the material from the tunnel. The crushing apparatus according to the invention is also eminently suitable for crushing quarried material. If desired, two or more such crushing apparatus may be mounted in series in order to reduce the size of crushed material in a series of stages with the crushed material discharged from one stage fed as in-feed material to a subsequent stage and, according to the size of crushed material required, a discharge chute may be mounted between each successive apparatus. Conveniently, each discharge chute may include means for opening and closing the same so that when open, material crushed by an immediately preceding apparatus is discharged for removal whereas, when closed, material is fed to the next successive stage for further crushing. Crushing apparatus in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is an end view of a crushing apparatus; Figure 2 is a cross section of the apparatus taken along line A-A of Figure 1; Figure 3 shows a sectional end view of inner and outer members of the crushing apparatus having different members of faces, and Figures 4 to 12 respectively show in sectional end views of different multi-faced combinations of the inner and outer members as well as different shapes of the multi-faced members. Referring to Figures 1 and 2, an inner member 10 having an extension 10A and outer member 20 having a bore 20A are mounted coaxially for relative rotation about axis X-X. The inner member 10 or the outer member 20 may be driven but, preferably, the inner member is driven by driving means not shown via a shaft 33. A crushing chamber 21 is, of general annular shape and converges from an inlet 22 to a discharge outlet 23. Inner and outer peripheral walls of the crushing chamber 21 are constituted by faces 24 and 25 respectively of the inner 10 and outer 20 members which are of right-conical shape. In the embodiments shown in Figures 1 and 2 the inner member 10 has nine faces 24 and the outer member 20 has eight faces 25. Attached to the inner member 10 are three radial arms 26 bearing teeth 27 which together serve, during rotation, to assist introduction and crushing of material fed into the crushing chamber 21 via the inlet 22. It will be appreciated that during rotation of the inner member 10, crushing is effected by inter-action of the material and the faces 24, 25 of the multi-faced inner 10 and outer 20 members since, during rotation, the radial distance between the confronting faces 24,25 on the inner 10 and outer 20 members changes continuously. Crushed material exits through the discharge outlet 23 and passes for subsequent or secondary crushing into a secondary crushing chamber 28. Prongs 29, 30 carried by the inner 10 and outer 20 members respectively serve not only to create secondary crushing but are shaped to assist discharge via a discharge channel D. Lubricant/coolant is fed into the crushing chamber 21 and secondary crushing chamber 28 via conduits 31 and 32. The number of faces of the inner 10 and outer 20 frusto-conical members differ in number as previously mentioned by at least one, but each face may also differ in shape and geometric configuration. Figures 3 to 12 show a number of different multi-faced configurations. A multi-faced inner member 10 having nine faces and a multi-faced outer member 20 having eight faces is one very effective combination of faces. Other combinations of faces are also effective. The inner 10 and outer member 20 may each have an even number of faces with the number of faces on each member differing by two. In such a combination of faces, a progressive crushing action is produced between two or more confronting pairs of faces at any particular angular position during relative rotation of the members. In arrangements having an even number of face combinations and where the number of faces in the respective members differs by two, e.g. Figure 9 where the inner member 10 has ten faces and the outer member 20 has 12 faces, it will be seen that, in the angular position shown progressive crushing is duplicated between confronting pairs of faces d/d' and i/f'. Similarly in Figures 10 and 11 where the faces are marked with the same reference letters, progressive crushing is duplicated between confronting pairs of faces a/a' and b/c' (Figure 10) and between confronting pairs of faces b,b' and e,f' (Figure 11). Referring to Figure 12, the inner member 10 has nine faces (a....i) and the outer member 20 has twelve faces a' ....l'. Thus, a difference in the number of faces of three exists between the inner and outer members. In such a multi-faced configuration of the inner and outer members, it will be seen from Figure 12 that three confronting pairs of faces are substantially parallel. In this arrangement progressive crushing, therefore, takes place between three pairs of confronting faces and, as with the arrangements of Figures 9, 10 and 11, a crushing apparatus according to Figure 12 is, in use, substantially in rotational balance. It will, therefore, be appreciated that (i) where the main and outer members each have an even number of faces which differ by two, crushing action is duplicated between two confronting pairs of faces, and (ii) where the inner and outer members each have a different number of faces which are respectively divisible by three, crushing action is triplicated between three confronting pairs of faces. A suitable combination falling under category (i) above is a six/eight facial arrangement. As indicated previously the faces may be flat, convexly curved or concavely curved. In contrast with conventional cone crushers, a crusher in accordance with the present invention possesses the advantage of reduced wear between the members since there is less shearing action of the input material with the lower angle of face motion of the respective members relative to the normal to the relevant face. The included angles α and β between the faces of the main member 10 and outer member 20 and the bases of their respective may fall within a range of 50° to 80° and, preferably, with a range of 55° to 70°. We have found that although the angles X and B may be different within the above ranges, an angle of 60° for both X and B is a practical and optinum relationship.

Claims: A crushing apparatus comprising a generally annual crushing chamber (21) having an inlet (22) for receiving material to be crushed and outlet (23) through which crushed material is discharged, the annular crushing chamber comprising coaxially mounted inner (10) and outer members (20), each member having a frusto-conical peripheral wall which converge towards the outlet with each peripheral wall having a different number of faces (24, 25) and means for creating relative angular movement between the inner (10) and outer (20) members whereby material introduced into the crushing chamber through the inlet (22) is crushed between the peripheral walls during relative rotation thereof and passage from the inlet (22) to the outlet (23), characterised in that the faces (24, 25) of each peripheral wall extend from the inlet (22) to the outlet (23) of the crushing chamber (21) whereby the outlet (23) is annular and is defined by inner and outer peripheral walls having a number of faces corresponding to the number of faces (24,25) of the peripheral walls of the inner (10) and outer (20) members, in that the inner member (10) includes an extension (10A) located within the outlet (23) and in that the extension (10A) has a peripheral wall having the same number of faces (24) as the inner member (10) Apparatus according to claim 1 or 2 characterised in that the outlet (23) is coaxial with the annular crushing chamber (21). Apparatus according to any one of claims 2 or 3 characterised in that when considered in coaxial cross-section, the peripheral wall of the frusto-conical inner member (10) diverges outwardly towards the outlet (23) and the peripheral wall of the frusto-conical outer member (20) converges inwardly towards the outlet (23) whereby the annular extent of the crushing chamber is progressively reduced from the inlet (22) to the outlet (23). Apparatus according to any preceding claim characterised in that one end of the inner member (10) is located in the region of the inlet (22) and includes at least two equi-angularly disposed arms (26) extending radially outwardly from the inner member (10). Apparatus according to any preceding claim characterised by at least one conduit (31, 32) for leading lubricant into the crushing chamber (21). Apparatus according to any preceding claim characterised in that the inner member (10) includes a shaft (33) coaxially disposed within a bore (20A) formed in the outer member (20). Apparatus according to claim 6 characterised by interdigitated prongs (29, 30) extending from the bore (20A) and the shaft (33) respectively for crushing in a secondary crushing chamber (28), previously crushed material discharged from the outlet (23). Apparatus according to any one of claims 1 to 7 characterised in that the inner peripheral wall has one face (24) greater or less in number than the number of faces (25) of the outer peripheral wall. Apparatus according to any preceding claim characterised in that the peripheral wall faces (24, 25) of the inner and outer members define right cones. Apparatus according to any preceding claim characterised in that each face of each peripheral wall (24, 25) is flat. Apparatus according to any one of claims 1 to 9 characterised in that each face (24) of the peripheral wall of the inner member (10) is convex and each face of the peripheral wall (25) of the outer member (20) is flat. Apparatus according to any one of claims 1 to 9 characterised in that wherein each face (24) of the peripheral wall of the inner member (10) is concave. An apparatus according to claim 1 characterised in that the angle of inclination between each face (24,25) of the multifaced peripheral wall and the base of the respective frusto-conical inner (10) and outer members (20) falls within a range of 50° to 80°. Apparatus according to any one of claims 1 to 7 characterised in that the number of faces (24, 25) on each of the inner (10) and outer (20) members is an even number and wherein the number of faces on the respective members (10), (20) differs by two. Apparatus according to any one of claims 1 to 7 characterised in that the number of faces (24, 25) on each of the inner (10) and outer (20) members is a multiple of three and the difference in the number of faces on the respective members (10), (20) is three.

Inventors: WASHBOURNE JIM, WASHBOURNE, JIM
Applicants: OXFORD BROOKES ENTERPRISES LTD, OXFORD BROOKES ENTERPRISES LTD.
Application year: 1992
Main classification: B02C2
IPC codes: E21B7, E21D9, B02C2