GB2278788A - Scrap/refuse impact crusher - Google Patents

Description

2278788 SCRAPIREFUSE CRUSHING DEVICE This invention relates to a crushing

device particularly f or scrap, industrial and/or domestic refuse which has a housing provided with a material feeding area and a material discharge area. A rotor is rotatable about a horizontal axis received in the housing and is provided with crushing implements which cooperate with abutments located in the housing for carrying out the crushing process.

A crushing device of this kind is known from DE-PS 36 43 529 wherein the material to be crushed is subjected to a direct crushing action through an angular area of approximately 180' and is fed thereafter to a material outlet of changeable size. Should the material put up a very high resistance against the crushing action, then the danger exists that by the time it reaches the material outlet, at which non-crushable material or material which is comparatively difficult to crush can be thrown out, considerable forces act upon the rotor and the abutments located in the housing. As a result of such forces, damage to the rotor will often occur. An unfavourable change of the dynamic behaviour of the rotor can, in an extreme case, lead to the functional breakdown of the entire crushing device.

It is an object of the present invention to provide an improved crushing device which substantially suppresses the peak force values arising during the crushing process, which lie way above the average required force requirement and which bring about an overexertion of the device during continuous operation.

This object is achieved according to the invention in that positioning elements are provided in the housing which comprise an initial tension which determine the position of the rotor and abutments relative to one another and behave elastically when the initial tension is exceeded, allowing a relative deflected movement of the rotor and abutments.

The invention has the advantage of also being able to crush large-sized material on a long crushing route. Large-sized material which puts up too high a resistance to crushing, is removed from the crushing cycle after running through the crushing route to a material discharge outlet, without exposing the crushing device to overloading and thus possible ensuing damage.

In order to immediately guide the rotor back into the original position after leaving it as a result of a grossly uneven distribution of the forces acting upon the rotor during the crushing process, the positioning elements are - 3 provided in one embodiment of the invention in the area of the rotor bearing arrangement and the abutments are formed rigidly, opposite the housing.

The positioning elements are preferably located between the rotor bearing and the housing in the aforementioned embodiment of the invention. With this embodiment (in contrast to arranging the positioning elements in the area of the rotor bearing) larger relative displacements of rotor and housing can be achieved.

If the rotor bearing is carried by a wedge-shaped hinged support, the pivot capability of which is activated after a preselectable force is exceeded, the amount of force determining the extent of pivot capability, then deflection movements of the rotor are made possible over the entire crushing route with approximately corresponding deflection strokes, with constantly changing radial direction of deflection.

In an alternative embodiment, the rotor bearing arrangement is connected such that it is fixed rigidly relative to the housing and at least one abutment is connected to the housing by means of pretensioned positioning elements, the elastic behaviour of the abutments preferably being coordinated such that a constant flow of material is maintained in the crushing chamber even when the corresponding abutments are deflected. A design of this type is particularly advantageous if the occurrence of high forces in local adjacent areas of the inner surfaces towards the rotor of the crushing chamber have to be taken into consideration. In this way only the abutments acted upon by particularly high forces move outwards, whereas the remaining abutments are further involved in the crushing process at this time.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIGURE 1 is a side view in partial section of a hammer crusher in its initial state showing the rotor which is deflectable when an initial tension is exceeded and abutments fixed to the housing; FIGURE 2 shows the hammer crusher of Figure 1 with the rotor 20 after deflection; FIGURE 3 is a side view of an alternative hammer crusher in section with a fixed rotor and abutments which deflect when an initial tension is exceeded.

FIGURE 4 shows a rotor bearing fastening as an alternative 25 to that shown in Figure 1; and FIGURE 5 shows a side view of the bearing area shown in r_ Figure 4.

Referring to the drawings, Figure 1 shows a rotor 3 mounted for rotation about a horizontal axis 2 in a housing 1 of a hammer crusher. At the periphery of the rotor 3, rotating hammers 5 are mounted to pivot about a respective horizontal axis 4. These hammers 5 cooperate with inner surface 6 of the housing 1 which surrounds the rotor 3 when the rotor 3 rotates in the direction of the arrow 7. Material to be crushed, like car bodies, steel containers or the like,, is fed from material feeder 8 to the hammer crusher. After successfully being crushed, this material is discharged from material outlet 9.

Each of the two bearings 10 which receive the axis 2 of the rotor 3 (the side views in Figure 1 and Figure 2 each show only one bearing side, referred to in the following) is fixed to a wedge-shaped supporting arm 11 received in a bearing seat 12. The end of the supporting arm 11 remote from the bearing seat 12, is guided via a bar 13 and pivot pins 14,15 such that it pivots in the housing. A tension rod 16 is linked to the centre region of the bar 13 which abuts the housing 1 through the intermediary of a spring 17. Abutting cylinder/piston arrangements 18 are located on the housing 1 on both sides of the supporting arm 11 with accumulators 19, which behave elastically when a preselectable pressure is exceeded.

If large-sized and not readily crushable material is fed to the crushing chamber of the hammer crusher, then an upward force of a magnitude exceeding the initial tension acts on the rotor 3 and causes it to deflect and raise the supporting arm 11.

Since the supporting arm 11 in its raised position can carry out a pivoting movement between the boundaries specified by the bearing seat 12 and the pivot capability is a function of the supporting arm, noncrushable large-sized material is transported from the material feeder 8 to the material discharge 9, without exposing the hammer crushers to excessively high forces on the way.

The embodiment shown in Figure 3 uses a fixed bearing arrangement for the rotor 3. The inner surf ace 6 of the housing 1, starting from the feeder 8 and continuing in the direction of rotation of the rotor 3, substantially forms a material discharge outlet 20, a grate section 21, a further material discharge outlet 22 and a baffle plate 23. These components are movable independently of one another in guides 24 and rest against pretensioned spring elements 25, so that their distance to the rotor 3 can be changed.

In the event of a force which exceeds the initial tension of the spring elements 25 being exerted on any one of the components during operation of the hammer crusher, then that component is deflected, but it is still capable of being involved in the crushing process. On the material discharge outlet 20 and baffle plate 23, the deflection takes the form of a pivoting movement around axes 26 and 27 which are fixed to the housing. The securing of the material discharge outlet 20 by means of the axis 26 disposed on the feeder side is furthermore a prerequisite for defining a crushing process in this area, independent of pivot state of the material discharge outlet 20.

Figures 4 and 5 show alternative securing means for the rotor bearing.

The bearing 10 which receives the axis 2 of the rotor is secured by screw connections 28 on the housing 1. The initial tension acting in the direction of the separating surfaces between the bearing 10 and the housing 1, is produced by conical spring washers 29. This initial tension exceeds the initial tension of the spring washers 30 by a preselectable amount determined by the interaction forces. The latter, cooperating with the pretensioned positioning elements 31, reliably guides the rotor bearing in the event of the forces arising during the permissible crushing of the scrap exceeding the initial tension of the spring washEtr 29. In so doing, the connecting elements 32 and 33 disposed on the bearing 10 which correspond with the spring washers 29 and 30, are spherical so as to allow a movement behaviour of the rotor which matches the field of force variable with time.

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Claims (8)

1. A crushing device f or scrap industrial and/or domestic refuse comprising a housing provided with a material feeding area and a material discharge area and a rotor which is rotatable about an axis received by the housing, the rotor being provided with crushing implements which cooperate with abutments located on the housing for carrying out the crushing process, and initially tensioned positioning elements provided on the housing which determine the position of the rotor and abutments relative each other and which behave elastically when the initial tension is exceeded, allowing a relative deflected movement between the rotor and abutments in the bearing area of the rotor.

2. A crushing device according to claim 1 wherein the positioning elements are located between a bearing arrangement for the rotor and the housing.

3. A crushing device according to claim 2 wherein the rotor is mounted in a bearing carried by a wedge-shaped hinged support which pivots after a preselectable force is exceeded, the magnitude of the f orce determining the amount of pivot movement.

4. A crushing device according to claim 1 wherein the - 10 abutments are connected with the housing by means of pretensioned positioning elements, the elastic behaviour of said abutments being coordinated such that a constant flow of material is maintained in the crushing chamber even when 5 the corresponding abutment is deflected.

5. A crushing device according to claim 4 wherein a discharge outlet is disposed beyond the material feeding area and is pivotable about an axis fixed to the housing.

6. A crushing device according to claim 1 or 2 wherein spring elements are provided for maintaining the initial tension of the positioning elements.

7. A crushing device according to claim 6 wherein Belleville spring washers or annular springs are used as spring elements.

8. A crushing device substantially as herein described 20 with reference to the accompanying drawings.