GB2221629A

GB2221629A - Crushing machine with protective shields

Info

Publication number: GB2221629A
Application number: GB8916328A
Authority: GB
Inventors: Gabriele Greiner
Original assignee: Lindemann Maschinenfabrik GmbH
Current assignee: Lyndex Recycling Systems Ltd
Priority date: 1988-07-23
Filing date: 1989-07-17
Publication date: 1990-02-14
Anticipated expiration: 2009-07-17
Also published as: GB2221629B; FR2634401B1; FR2634401A1; CH681065A5; AU625367B2; ES2015729A6; DE3825151C2; GB8916328D0; DE3825151A1; AU3880389A

Description

4 ROTOR HAVING PROTPECTIVE SHIELDS FOR A cRUSHING MACHINE r) 1 The

invention relates to a rotor having protective shields for a crushing machine.

is Such crushing machines can, for example, be hammer crushers or mills which comprise a stationary housing in which a rotor having protective shields is rotatably mounted. At the inlet of the housing and on its inner side is an anvil which cooperates with crushing tools attached rigidly or movably to the rotor.

of hammer crushers these hammers are between the di scs of the rotor whi ch plurality of discs mounted on a shaft to therewith. For this purpose the rotor, to a quickly rotating drive, has a plural rods passing through the discs parallel t shaft but offset eccentrically from i crushing tools or hammers are mounted rotate freely. Crushing occurs as a result of the interaction of the hammers with both the stationary anvil at the material inlet and with the inner wall or the floor of the housing, which acts as a counter tool against which the material is flung or over which it is drawn.

In the case t on whi so that mounted to pivot comprises a rotate usually coupled ity of axle o the rotor ch the they can In operation certain regions andlor parts of the crushing machine are subjected to particularly high wear and tear by the material to be crushed, which exerts forces on these regions or parts in many different directions.

The zones which undergo particularly severe wear and tear are those around the inner walls of the housing, the housing floor and, in the rotor region, around the rotor body or, in the case of a multipart rotor construction, around the discs forming the rotor body - particularly their outer surfaces, i.e. their 2 peripheral surfaces and the surfaces adjacent thereto -, flanges, spiders or the like and, in addition, the tools carried by the rotor, for example the hammers.

Especially if the material to be crushed consists completely or partly of metal, the rotor body suffers considerable wear due to abrasion and pieces of material striking it. After a relatively short period of operation so much metal is torn or worn away, in particular from the outer surfaces of the rotor body or the rotor discs, that the parts forming the rotor body become useless and have to be exchanged.

So as to increase the service life of the machine parts that are subject to wear, protective shields have been provided which cover the affected zones and can be exchanged when worn. The rotor body, for, example the discs of which it is largely made up, is or are covered -0 by protective shields according to a technique known from DE-PS 26 05 1-51. Protective shields and hammers are each arranged on a common axle rod and can be detached by pulling and removing the axle rod from the region of the supporting or rotor body by means of a special dismantling device and can then be exchanged. After removing an axle rod the protective shields lie loosely on the rotor discs and, like the hammers, are freely accessible and exchangeable.

In a construction known from DE-PS 33 27 204 the hammers and protective shields are arranged on different axle rods, which can however be pulled or ejected in the same manner by a special device known for example from DE-AS 24 37 793.

3 c The aforementioned proposals of possible ways of attaching and exchanging the protective shields substantially fulfill their purpose. However certain factors, in particular those determining the time needed for an exchange, are disadvantageous in this construction. In the two previously known constructions the space and time needed to remove the axle rod from the region of the rotor body are considerable because the dismantling and installing devices used therefor have to be changed over often. Depending on the length of the rotor, an axle rod two meters or more in length must be pulled out, plus the length of the special dismantling device for removing the axle rod from the region of the rotor body so that the protective shields are freely accessible. Since the removal or pulling out of the axle rod must be done stepwise for technical reasons the time factor adds to the constructional and space consuming disadvantages.

The installation and removal of the axle rods, of which in practice six to twelve are provided per rotor, is done with a special dismantling device by means of which the axle rods can be pulled out or removed. it is true that the individual detached protective shields still lie loosely on the peripheral surfaces of the rotor discs after the axle rods have been dismantled, but they must nevertheless be adjusted so that the bores of their supporting elements are aligned with the respective axle rod. In this position the axle rod, when proceeding stepwise, is inserted through the bore of each protective shield in a row, and each individual protective shield, of which 10 to 13 are lined up or arranged axially over the Length of the rotor, is centred and secured in this way.

1+ A further disadvantage with the known constructions lies in the expensive storage, which is determined by the number and the different types of the protective shields required to equip the rotor. Depending on the arrangement or number of hammers, whether 12, 16 or 24 are provided, in practice between 74 and 84 individual protective shields, some being different, are required to equip a rotor. This also means that when installing new protective shields the operator must be able to judge which protective shield is to be installed, since both the protective shields on the rotor ends and the protective shields in the region of the hammer are different from, for example, the other protective shields. In combination with the necessary adjusting work on each individual protective shield lining up the bores of the protective shields with the axle rod this necessary selection and arrangement of the respective corresponding protective shields involves a considerable amount of effort. The method explained above in the case of the known constructions does function efficiently, but it requires a lot of time and manpower because of the work necessary to adjust the protective shields.

It is an object of the invention to protect the outer surfaces of a rotor body from wear with protective shields which can be exchanged more quickly and more simply and using less space and manpower.

To this end according to the invention the protective shields are secured to the rotor by a form-fitting (form-locking) direct connection or attachment. "Direct connection or attachmenC in this connection means one that does not require additional securing elements, in particular the known axle rods, whereby space and time is saved when exchanging. It is particularly advantageous if the protective shields have on their side remote from the region subject to wear at least one attachment rail which can be inserted into at least one respective profiled recess in the rotor.

The time required for exchanging the protective shields is greatly reduced by the possible ways of detachment according to the invention, and is only a fraction of the time required before because the whole time-consuming procedure for drawing out or pressing out the axle rods is dispensed with. To centre the protective shields using the prior art methods, as a rule two operators are necessary, of whom one attends to the alignment of the bore of each protective shield with the axle rod and the other operates the manually operated crane device and monitors the stepwise movement of the axle rod and carries out the necessary technical manipulation therefor. However, owing to the advantages explained above in the construction according to the invention only one operator is necessary for exchanging and inserting the protective shields. The time gained by this is just as obvious as the considerably reduced space requirement compared with that required in the already known dismantling devices in which the axle rods must be removed completely from the region of the rotor body, i.e. in the example given, at least two meters of space must be available for movement of the axle rod and furthermore additional space for setting up the dismantling device in the direction of movement of the axle rod.

Moreover, with the proposal according to the invention, when installing the protective shields in a favourable case only six relationships have to be set up, i.e. with a predetermined and unchanged hammer pattern, with continuous protective shields completely 0 6 covering the length of the rotor up to a maximum of only six varieties or different kinds of protective shield are necessary, which are classified by the slits for the hammers which are provided or allowed for in the surface of the protective shields.

In a further embodiment of the invention the length of a protective shield on the rotor can be selected freely up to a maximum over the length of the rotor within the scope of the possibilities of attachment, i.e. where rotor discs are present which allow insertion. This measure further facilitates handling tile protective shields when installing and dismantling. Furthermore the room for movement necessary when sliding the protective shields in and out, which in the case of a protective shield which covers the whole rotor length can amount to about two meters, can be reduced to about half the rotor length, i.e. to about one meter, if the protective shields are selected with a length that only covers half the full length of the rotor. Another possibility is that the protective shields cover with their respective covering parts of the rotor disc width of the neighbouring rotor discs, i. e. a construction with several individual protective shields, which then have to be removed individually in the sequence in which they were mounted. The storage costs are reduced considerably because with six axles distributed on the periphery of the rotor only twelve protective shields are necessary instead of seventy-four or eighty-four as in the known constructions. Where each single protective shield covers the full rotor length, only six protective shields would be necessary to equip the rotor completely. It is however also possible within the scope of the invention to have fewer shields around the periphery of the rotor than the number of axles, for 7 example, four protective shields arranged on the periphery of a rotor having six axles.

Advantageous developments of the protective shields according to the invention are set forth in the subclaims.

Further features of the invention will now be explained more fully with reference to the exemplary embodiments shown in the drawings, in which:

Fig. 1 Fig. 1 in the mounted dash-dot Fig. 2 Fi 9. 3 shows a longitudinal section through a crushing machine having a rotor designed according to the invention, shows a cross-section through the rotor along the line 11-11 in Fig. 3, shows a longitudinal section along line III-III in Fig. 2, Fig. 4 shows a diagrammatic representation of a complete hammer crusher rotor having a cover, indicated in outline, for securing the attachment rails axially, and Fig. 5 and 6 show modifications of the rotor, inter alia to show the arrangement of the protective shields.

The crushing machine indicated generally by 1 in is, as an exemplary embodiment, a hammer crusher housing 2 of which a rotor 3 and its shaft 4 are to rotate. This housing is only indicated by lines in Fig. 3. Figs. 1 and 3 show its end walls 5, an indication of its bearing 6, and its side walls 7. A plurality of, for example, circular rotor discs 8 can be keyed on to the rotor shaft 4 by a key 9 to rotate therewith. The invention is not, however, I 8 only restricted to a disc rotor but can also be applied to supporting bodies of other shapes, for example a spider rotor or an integrally cast rotor body. The shaft 4 can be made to rotate by means of a drive (not shown). Each of the rotor discs 8 consists of a disc body or flange 8a provided with a hub 8b. The rotor discs lie with their hubs 8b side by side and close together on the shaft 4. The rotor discs 8 on the shaft 4, with the hubs 8b and the flanges 8a, form the rotor body or the supporting body of the rotor 3 of the hammer crusher.

Parallel to the shaft 4 but offset radially therefrom are axle rods 10 which are all at the same distance from the shaft 4 and pass through the rotor discs 8 or the bores 8c in the rotor discs or flanges 8a. The axle rods 10 serve as a bearing for the hammers 11, which are mounted so that they can rotate freely on the axle rods. The hammers 11 have an eccentric form and project outwardly in the manner shown in Fig. 1 in the operating condition of the hammer crusher. In Figs. 2, 3 and 4 the rotor 3 in operation, that is to say at a standstill.

is not As a rule, two hammers 11 do not lie closely adjacent to one another. Rather the hammers are distributed in the longitudinal direction of the rotor and on its periphery as can be seen for example in the modifications shown in Figs. 5 and 6.

In order to prevent wear from occurring on the outer surfaces, i.e. the peripheral faces and their neighbouring surfaces of the rotor discs 8 and flanges 8a, further wearing elements are attached to the rotor 3, namely protective shields 12, in addition to the hammers. Of the protective shields 12 in the exemplary 9 embodiments shown, two are arranged over the entire length L of the rotor 3. This however is not essential for the invention; other constructions are also possible within the scope of the invention and the length 1 of a protective shield 12 up to a maximum over the rotor Length L can be chosen freely within the scope of the possibilities of attachment to the rotor, i.e. in relation to the exemplary embodiment, of the possibilities of attachment to the rotor discs, e.g. in such a way that a single protective shield 12 covers the entire length L of the rotor 3 or, as another example, with individual protective shields each covering with their covering parts 12a half the rotor disc width (b) of respective neighbouring rotor discs 8a.

The protective shields 12 can for example, as shown in the exemplary embodiments, be shaped as segments of a circle. On the underside 12c of the protective shields 12 or of the covering part 142a remote from the wearing region 13 is an attachment rail 14, which may be profiled and which can be inserted coaxially into a correspondingly profiled recess 15 in the rotor 3 or in its discs 8. The profiled attachment rail 14 on the protective shields 12 can for example have a trapezoidal cross-section 14a which converges towards the wearing region 13. Alternatively the attachment rail 14 can have a cross-section 14a made of two trapezia with their shorter parallel sides 14b adjoining one another.

The axial and peripheral distance between two neighbouring protective shields 12 or the covering parts 12a of the protective shields which, in the exemplary embodiment shown, each cover half the length L of the rotor, is as small as possible and is as a rule smaller than shown in the drawings. Within the scope of the invention it is possible for the whole assembly of protective shields, when mounted, either substantially to cover the periphery of the rotor or the rotor discs to be protected or to form a cylinder or protective jacket sealed to the greatest possible extent. However, at least everywhere where a hammer 11 projects from the periphery of the rotor, the jacket of the rotor has a slit 12c.

The respective attachment rail 14 of the protective shield 12 projecting beyond the end rotor disc 8d of the rotor is secured against axial displacement in the operating condition (see Figs. 3 and 4) by means of a is cover 16 which engages in a groove 14c i-n the attachment rail and is attached to the end rotor disc 8d. When it is necessary to exchange the protective shield 12 this cover 16 must first be removed before the protective shield can be pushed out axially.

The physical dimensions of a rotor according to the invention must be selected so that installing and dismantling the protective shields in the upper dead centre position of a protective shield (see Fig. 2) is not obstructed in any way by the hubs of the hammers suspended on the axle rods or even by the hammers themselves.

T 11

Claims

What we claim is:

1. A rotor with protective shields for a crushing machine, wherein the protective shields are removably secured to the rotor body by a form-fitting direct connection or attachment.

2. A rotor according to claim 1 wherein the protective shields are adapted to be pushed on to and withdrawn from the rotor parallel to the axis of rotation of the rotor.

3. A rotor according to claim 1 or claim 2 wherein a plurality of protective shields are arranged along the length of the rotor.

4. A rotor according to any preceding claim wherein the protective shields have on their side remote from the wearing region at least one attachment rail which can be inserted into at least one respective profiled recess in the rotor body.

5. A rotor according to claim 4 wherein the rotor body comprises an assembly of discs and the attachment rail or rails engage(s) in aligned, profiled recesses in the discs.

6. A rotor according to claim 4 or claim 5 wherein the attachment rails on the protective shields have a trapezoidal cross-section which converges towards the wearing region.

7. A rotor according to any one or more of claims 4 to 6 wherein the attachment rails have a double- trapezoidal cross-section made up of two trapezia with their shorter parallel sides adjoining one another.

12

8. A rotor according to any preceding claim, said rotor having a plurality of protective shields distributed around its periphery with their longitudinal edges adjoining, and having hammers mounted thereon on axles that are parallel to the rotor axis and are radially adjacent to the longitudinal edges of the protective shields.

9. A rotor according to claim 8 wherein the number of protective shields around the periphery of the rotor is smaller than the number of hammer axles.

10. A protective shield for a rotor according to any preceding claim having an outer wearing surface and having on its inside a longitudinal attachment rail of trapezoidal cross- section that converges towards the outer surface of the shield.

11. A protective shield for a rotor according to any one of claims 1 to 9 having an outer wearing surface and having on its inside a longitudinal attachment rail of double trapezoidal cross- section with the shorter parallel sides of the two trapezia adjoining one another.

12. A rotor for a crushing machine according to claim 1 substantially as hereinbefore described with reference to Figs. 1 to 3, 4 or 5 of the drawings.

13. A protective shield for a rotor for a crushing machine according to claim 10 substantially as hereinbefore described with reference to Figs. 1 to 3, 4 or 5 of the drawings.

Published 1990 atThe Patent Office.State House. 6671 HighHolborn. LondonWC1R4TP. Further copies maybe obtainedfrom, The Patent MceSales Branch. St Mary Cray. Orpingtor. Kei.t BR5 3PX. Pr,rsed by Mjl:jplex techmques lta. St Mary Cray. Kent. Con. l!Q7 1 1