EP0666111A1 - Rotor for impact crusher - Google Patents

Abstract

The hammer rotor consists of a series of discs (10) fixed to a rotary shaft, and a series of lengthwise radial and symmetrical hammers (14) set in peripheral recesses in the discs and held in place by locking members (24) and detachable wedges (42), each supported by a projection (40) on the edge of a disc recess. The hammers are removed by sliding each wedge axially and extracting it radially from between two adjacent discs. Each hammer has symmetrical recesses in its front and rear faces, and each wedge has a C-shaped section with an outer surface corresponding to the shape of a hammer recess.

Description

The present invention relates to a rotor for an impact crusher comprising a series of discs fixed on an axis of rotation, a series of symmetrical longitudinal beaters, radially projecting from the discs and arranged in open peripheral housings of the discs and a system for holding the beaters in their homes.

This kind of crusher is commonly used, for example, for crushing rocks. The material to be crushed is poured onto the rotor which is driven around its axis of rotation and the crushing of the material occurs, either under the impact of the beaters, or when the material smashes against screens on which it is projected by the rotor. Due to the intensity of the impact on the beaters, they are exposed to rapid wear and must be replaced relatively often. To halve the frequency of replacement of the beaters, it is known to use symmetrical beaters which can be turned over when their leading face is worn.

Document AT-B-351 906 proposes a rotor with symmetrical beaters which can be turned over when one of their attack faces is worn. The beaters have on their front and rear flanks two symmetrical grooves with rounded section and are held in place on the rear flank by a round rod and, on the front flank, by wedges fixed by wedge effect on pointed noses forming the edge. exterior of housing. These beaters are not rigidly fixed and can oscillate around their rod and holding blocks to lock in a determined position under the effect of centrifugal force. Since there is no rigid attachment the beaters must be made of a material relatively ductile such as steel or manganese, this however at the expense of wear resistance.

In this beater the wedges can only be released tangentially from the nose on which they are stuck. The beaters must therefore be released axially from the rotor with a view to their overturning or replacement, which often constitutes a handicap.

Document DE-A-21 47 920 describes a rotor with beaters which are held in place by removable wedges which allow radial disengagement of the beaters. However, these beaters have the drawback of not being symmetrical, and therefore of not being able to be turned over when their leading face is worn. In addition, there is also no rigid fixing of the beaters, therefore no possibility of using materials with properties of optimal resistance to wear.

The object of the present invention is to provide a new rotor for a crusher with an improved fixing system for the beaters which facilitates the replacement and turning of the beaters and which allows the use of very hard alloys for producing the beaters.

To achieve this objective, the rotor proposed by the present invention is characterized by a system for locking and rigid fixing of the beaters constituted by the combination of a locking system with progressive tightening on the side of the rear face of the beaters and, on the side from the front face of the beaters, axially removable shims each carried by a protruding nose from the outer edge of the housing.

When the beaters are unlocked, each wedge is released from its nose by axial sliding and radial extraction between two discs. Once all the shims in the same row are thus removed, the beater can be released radially from its housing. This possibility of disassembly significantly reduces maintenance time.

Each beater has on its front face and on its rear face longitudinal throttles of profiled section respectively intimately married by the rear face of each wedge and urged radially and tangentially by the locking system to ensure rigid fixing of the beaters in their housings. This rigid attachment makes it possible to use very hard beaters, for example made of chrome cast iron with a hardness greater than 63 Rc and thus significantly improve the wear resistance.

• la Figure 1 représente une vue en perspective d'un rotor de concasseur à percussion selon la présente invention ;
• la Figure 2 représente une vue axiale d'une des bases du même rotor ;
• la Figure 3 représente le rotor sans les battoirs et
• la Figure 4 représente une vue en perspective d'une rondelle de verrouillage des battoirs.

Other features and characteristics will emerge from a preferred embodiment presented below, by way of illustration, with reference to the appended drawings in which:

• Figure 1 shows a perspective view of an impact crusher rotor according to the present invention;
• Figure 2 shows an axial view of one of the bases of the same rotor;
• Figure 3 shows the rotor without the beaters and
• Figure 4 shows a perspective view of a locker washer.

The rotor shown in the Figures consists essentially of a series of discs 10 which are fixed on a horizontal central axis not shown which, in operation, is actuated to rotate the discs 10 in the counterclockwise direction, seen in the Figures. Each of the discs 10 comprises, at its periphery, a series, in the example shown, four recesses or housings 12 aligned longitudinally with one another. In each row of housings 12 is disposed a beater 14 intended to strike the material to be crushed during the rotation of the rotor.

As shown in the Figures, each beater 14 has a symmetrical shape with respect to a radial plane of the rotor, with two symmetrical attack faces 16 and 18, which allows the beater 14, in the event of wear of the face 16, to be turned over to work with the face 18. Each beater 14 also has, in the middle region, two symmetrical profiled throttles 20 and 22 serving to fix and wedge the beater in their housings 12.

This fixing is provided by a locking system 24 located on the rear face of the beaters 14, seen in the direction of rotation. This system comprises a fixing rail 26 which is welded to each of the discs 10 through the housings 12. This rail 26 has a series of cylindrical cells 28 (see Figure 3) open towards the outside and extending in the mass of the rail by a female thread 30. The rail 26 also has, over its entire length, on the beater side 14, a seat 32 which extends to the cells 28 and opens the latter on the beater side 14. This seat 32 serves housing a key 34 as shown in Figures 1 and 2, while each cell is intended to receive a thick cylindrical washer 36 (Figures 1 and 4). Each washer 36 has a bevel cut 38 (Figure 4) making an angle of about 15 ° with the generator. When the washers 36 are introduced into their cells 28, these bevelled parts cooperate with the key 34, so that by tightening the washers 36 in the cells 28 using a screw not shown, the bevelled part 38 of the washers urges the key 34 towards the beater 14 to wedge the latter at its throttle 22.

Each housing 12 has, on the side of the front face of a beater 14, a projecting nose 40 directed towards the fixing system 24. Each nose 40 is capped with a removable wedge 42 having generally a section in the shape of "C" the inner face of which matches the shape of the nose 40 and the outer face of which has a contoured contour which matches the constriction 20 of the front face of the beater 14. Each beater 14 is thus securely anchored between the wedges 42 and the locking system 24 , both radially and tangentially.

Indeed, when the washers 36 are tightened, the oblique front edge of the key 34 engages the upper edge of the throttle 22 of the beater. The thrust in the tangential direction ensures a tightening between the shims 42 and the beater as well as a very precise positioning of the beater 14 thanks to the complementary contoured contours of the throttle 20 and the shim 42. The key 42 also ensures, during the tightening of the washers 36 a radial thrust on the beaters 14 to wedge them by the inner edge of the throttle 22 against the inner edge of the fixing rail 26. The beaters 14 are thus positioned correctly and rigidly fixed between the system lock 24 and shims 42.

To replace or return a beater 14, it suffices to release the locking system 24 by unscrewing the screws of the clamping washers 36 of the key 34. Then, it suffices to slide each wedge 42 axially out of its nose and to withdraw them radially. between two neighboring discs 10. Once all the shims 42 of the same row are thus removed, it is easy to disengage the beater 14 radially from its housing 12, the spacing between the tip of the nose 40 and the locking system 24 being sufficient to allow the extraction of the beater. The reassembly of a beater has the same phases in reverse order.

Claims (5)

Rotor for impact crusher comprising a series of discs (10) fixed on an axis of rotation, a series of symmetrical longitudinal beaters (14) radially projecting from the discs (10) and arranged in open peripheral housings (12) of the discs (10) and a system for holding the beaters (14) in their housings (12), characterized by a system for locking and rigid attachment of the beaters (14) constituted by the combination of a progressive tightening locking system ( 24) on the side of the rear face of the beaters (14) and, on the side of the front face of the beaters (14), axially removable shims (42) carried each by a projecting nose (40) from the outer edge of the housing . Rotor according to claim 1, characterized in that, when the beaters (14) are unlocked, each wedge (42) is released from its nose (40) by an axial sliding and a radial extraction between two adjacent discs (10). Rotor according to claim 1, characterized in that each beater has in the median region of its front and rear faces two symmetrical profiled throttles (20, 22). Beater according to claim 3, characterized in that each shim (42) is generally in the shape of a "C" with an outer face of contoured contour matching the corresponding constriction (20) of the beater. Slapper according to any one of Claims 1 to 4, characterized in that the locking system (24) comprises a fixing rail (26) welded longitudinally on each disc (10) in the rear region of the housings (12) and provided threaded cylindrical cells (28) open on the side of the beater (14) and a longitudinal seat (32) serving housing to a fixing key (34), cylindrical washers (36) with a bevel cut (38) intended to be screwed into said cells (28) and to act, by means of the bevel cut (38) the key (34) for moving the latter in the rear throttle (22) of the beater (14) as the washers (36) are tightened in the cells (28).

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