GB2076691A

GB2076691A - Impact-mill rotor

Info

Publication number: GB2076691A
Application number: GB8113674A
Authority: GB
Original assignee: HAZEMAG ANDREAS KG; Hazemag Dr E Andreas KG
Current assignee: HAZEMAG ANDREAS KG; Hazemag Dr E Andreas KG
Priority date: 1980-05-08
Filing date: 1981-05-05
Publication date: 1981-12-09
Also published as: JPS579341U; ATA190281A; JPS607803Y2; DE8012521U1; ES258180Y; FR2481952A3; AT378920B; ES258180U; GB2076691B; FR2481952B3

Abstract

An impact-mill rotor has blow or beater bars clamped in axially parallel slots in the rotor by means of wedges which are held in the clamping position by a pressing device. This device comprises a threaded spindle and a cooperating pressing nut. A set of springs, preferably consisting of conical or Belleville springs (17), is disposed on the threaded spindle (13) between the pressing nut (15), which can be screwed thereon, and a ring (16) mounted at one end. The pressing device (1) is guided at the ends (14, 16) of the threaded spindle in a respective recess (20, 12) of the rotor (5) and of the wedge (2). That recess (12) against whose edge (11) the spring set is applied is of such a depth and so guides the threaded spindle end and the ring (16) that the threaded spindle can be pushed therein and swung out laterally to such an extent that the other end (14) of the threaded spindle can be removed from the associated recess (20). <IMAGE>

Description

SPECIFICATION Impact-mill rotor The present invention relates to an impact-mill rotor whose blow or beater bars are clamped in axially parallel slots in the rotor by means of wedges which are held in the clamping position by a pressing device which comprises a threaded spindle and a pressing nut cooperating therewith.

In the known pressing devices of this type, either the pressing nut is firmly connected to the wedge, or the internal thread is provided in the wedge itself (see United States Patent Nos.

2 747 803 and 3 151 816). Therefore, it is necessary for the threaded spindle to be screwed into the wedge before the wedge is inserted, and thus this threaded spindle, conversely, cannot be removed upon releasing the wedge until the wedge has been knocked loose, so that under this often very robust handling the threaded spindle and the thread provided in the wedge can be easily damaged. Furthermore, in this design the wedges are complicated and expensive.

It is the object of the present invention to render the pressing device independent of the wedge, so that it can be inserted only after installing the wedge and can be removed before the wedge is knocked loose. It is also intended to ensure that, after any possible settlement of the wedge and beater bar, the fastening isstill forcelocked.According to the invention, this is achieved in that a set of springs, preferably consisting of conical or Beileville springs, is disposed on the threaded spindle between the pressing nut, which can be screwed thereon, and a ring mounted at one end, and in that this independent pressing device is guided at both ends of the threaded spindle in respective recesses of the rotor and of the wedge, of which that recess against whose edge the spring set is applied is of such a-depth and so guides the threaded spindle end and the ring fastened thereto that the threaded spindle can be pushed therein and swung out laterally to such an extent that the other end of the threaded spindle can be moved out of the associated recess.

In such a design, it is sufficient to screw back the pressing nut to a greater or lesser extent for the springs to be relaxed and for such a clearance to be formed between them and their contact surface at the wedge or rotor that it is possible to insert the threaded spindle with the ring somewhat further into the recess so that its other end leaves the associated recess and can then be swung out laterally and removed from the firstmentioned recess.

The recess into which the end of the threaded spindle provided with the ring engages is, preferably, provided in the wedge, because it can be better formed therein, at best as a simple smooth bore, whereas the other recess is formed by a flat ring welded on to the bottom of the rotor slot and whose hole has an angular shape corresponding to the cross-section of the associated end of the threaded spindle, thereby preventing any rotation of the threaded spindle when fitted in position. Preferably, the threaded spindle has at this end a hexagonal head and the ring hole a corresponding hexagonal shape.

To enable the ring inserted into the bore to allow lateral swinging out of the threaded spindie, it is preferably provided with a convex outer surface so that exact guidance of the spindle occurs in any position. However, this is not absolutely necessary. If the ring is not very thick, it may therefore also be formed with a cylindrical outer surface and with a certain amount of play in the bore, which makes possible adequate swinging out of the spindle.

Upon tightening the pressing nut against the spring set, the latter is applied against the wedge or against the rotor and thus effects a resilient transmission of the pressure exerted by the pressing nut, which prevents the wedge from being knocked loose and, moreover, holds the wedge constantly with a given force in the clamping position, so that it is not possible for any settlement play to occur and, at the same time, prevents any unscrewing of the pressing nut on the spindle.

The accompanying drawing illustrates a cutaway portion of an impact-mill rotor with a pressing device of this type, in which: Figure 1 shows the pressing device in the operative position, and Figure 2 shows it in the swung-out position for insertion or dismantling.

The pressing device, generaliy designated 1, serves to press a wedge 2 against a beater bar 3 which is inserted in an axially parallel slot 4 of an impact-mill rotor 5. In this case, the wedge is supported against one side wall 6 of the slot 4, whereas the beater bar 3 is positioned against the other side wall 7 and is held in the radial direction by a rib 8 which engages a corresponding longitudinal groove 9 of the beater bar.

The wedge 2, which is guided by a spring 10 against lateral displacement, has a simple bore 1 2 in its surface 11 facing towards the rotor axis. It is held in its clamping position by the pressing device 1 which comprises a threaded spindle 1 3 with hexagonal head 14, a pressing nut 1 5 which can be screwed on to the spindle, a centering ring 16 mounted on the free end and a number of conical or Belleville springs 1 7 which are disposed on the threaded spindle between the pressing nut 15 and the ring 16. This pressing device constitutes an independent component.

A not-very-thick guide ring 1 9 is fastened, for example welded, on to the base surface 1 8 of the slot 4. The spindle head 14 can be inserted into the recess 20 formed by this ring, and, the inner contour of the ring is so designed that the spindle head and thus the spindle cannot rotate. The centering ring 16, which is also relatively flat, has an outer diameter which so fits into the bore 1 2 that the threaded spindle can be pivoted laterally at its top end. Preferably, the outer surface of the ring is convex-shaped.

The pressing device 1, which constitutes a separate component, is extremely simple to use.

Before insertion, the pressing nut 1 5 is screwed along the threaded spindle 1 3 towards the spindle head 14 until the Belleville springs 1 7 are fully relaxed and, if necessary, have a certain amount of play. After the loose insertion of the wedge 2 between the beater bar 3 and the slot side wall 6, the pressing device 1 is then inserted obliquely from one side, with the free end of the threaded spindle 13 and the centering ring 1 6 mounted thereon, so far into the bore 1 2 that the other end of the threaded spindle with the spindle head 14 can be swung over the edge of the guide ring 1 9 and fitted into the recess 20 formed by the guide ring.The pressing nut is then screwed against the Belleville springs 1 7 until they apply the desired pressure against the surface 11 of the wedge 2.

The removal of the pressing device proceeds in the reverse order. If the pressing nut can no longer be turned on the spindle or only with difficulty, as a result of deposits, deformations caused by wear or corrosion, the free-standing spindle can simply be burnt through with a weiding torch. Admittedly, the spindle itself is no longer usable in that case, however, because it is a matter here of a commercially available screw or bolt, replacement with a new one is cheaper than a protracted operation to free the spindle thread. The remaining parts are further utilised.

If the rotor consists of individual discs arranged spaced apart on the shaft, it is also possible for the swinging out of the pressing device 1 to be carried out transversely to the discs and to the plane of the Figures.

Of course, the pressing device can also be inserted in the reversed position if the bore 12 is provided in the rotor 5 and the flat recess 20 and the ring 19 are provided on the wedge 2.

Claims

1. An impact-mill rotor whose blow or beater bars are clamped in axially parallel slots in the rotor by means of wedges which are held in the clamping position by a pressing device which comprises a threaded spindle and a pressing nut cooperating therewith, characterised in that a set of springs, preferably consisting of conical or Belleville springs (17), is disposed on the threaded spindle (13) between the pressing nut (15), which can be screwed thereon, and a ring (16) mounted at one end, and in that this independent pressing device (1) is guided at the ends (14, 16) of the threaded spindle in a respective recess (20, 12) of the rotor (5) and of the wedge (2), of which that recess (12) against whose edge (1 1 ) the spring set is applied is of such a depth and so guides the threaded spindle end and the ring (16) that the threaded spindle can be pushed therein and swung out laterally to such an extent that the other end (14) of the threaded spindle can be removed from the associated recess (20).

2. An impact-mill rotor as claimed in claim 1, characterised in that the recess (12), against whose edge the spring set is applied, is provided in the wedge (2) and is designed as a smooth bore.

3. An impact-mill rotor as claimed in claim 2, characterised in that the other recess (20) is formed by a flat ring (19) welded on to the bottom of the rotor slot (4), the hole of which ring having an angular shape corresponding to the crosssection of the associated end (14) of the threaded spindle (13).

4. An impact-mill rotor as claimed in claim 1, characterised in that the ring (1 6) has a convex outer surface.

5. An impact-mill rotor substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

6. An impact-mill having a rotor as claimed in any one of the preceding claims.