DE8520032U1 - Hammer mill with rotor parts protected against wear by protective agents - Google Patents

Description

P265

Patent application

Ing. Hans Lenz, Borngasse 8, 6470 Büdingen 8 Rinderbügen

Hammer mill with rotor parts protected against wear by protective agents

The invention relates to hammer mills with rotor parts protected against wear by protective means.

The rotors used in hammer mills are often designed as disc rotors. Between the discs, axles are inserted on which hammers swing. The hammers perform the tearing work by being moved close to the edge of an anvil. The outer peripheral edges of the discs are subjected to particularly high temperatures during the grinding process.

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Exposed to wear and tear. In order to prevent or slow down the premature destruction of the discs, the outer peripheral edges of the discs must be protected with highly wear-resistant material, for example by welding. This is done in the hammer mill itself or in a workshop after the rotor, which weighs several tons, has been removed. The time required for all repair work is a significant cost factor. The easier repair work can be carried out, the more cost-effective the operation. This applies regardless of the material costs.

But not only the outer peripheral edges of the discs are subjected to high stress, but also the discs themselves are exposed to high impact, shock and lateral bending forces, so that they can develop cracks and occasionally break out. It is therefore considered necessary to select high-quality material for these discs that can withstand these stresses, e.g. KAR 30 material number 18 8 45 with Brinell hardness

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KP/mm and 124-145 KP/mm tensile strength. In other rotor designs, the outer peripheral edges of the disks are protected by protective caps made of highly wear-resistant cast steel. The side walls of the caps are provided with holes through which the hammer axes are guided, so that the caps are also held in place by the holes. In practical operation, despite special tempering measures, it often happens that individual caps break. Equipping a rotor with many such caps, which give the rotor an almost closed shell surface, is very labor-intensive and cost-intensive.

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In a different design of the rotors, instead of disks, arm crosses are mounted on the rotor axis, between which the hammers swing. In this design of the rotor, protective caps are only arranged at the ends of the arm crosses. Even if the number of caps is significantly lower than with a disk rotor, these cast and tempered caps must also be replaced more often, since experience shows that wear and damage are great.

The invention therefore aims to improve rotors for hammer mills in several respects. The work and cost involved should be reduced and the function of the hammer mill should be improved.

This problem is solved by the teaching according to claim 1. The rotor, regardless of whether it is a disc or spider rotor, is covered and protected by sleeve parts over its entire length. The sleeve parts are made of highly wear-resistant material and can be cast parts.

In a disc rotor, two half shells can form the sleeve according to claim 2.

If the rotor is designed as a cross arm rotor, then according to claim 3, sufficient free space between the legs, which would be absent in the area between the cross arms with a circular sleeve, can be designed more favorably by appropriate design. Various types of fastening of the sleeve parts are shown in claims 4, 5, 6 and 7, while claims 8 and 9 deal with the arrangement and design of the division planes.

Without removing the sleeve, the worn

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It is also possible without difficulty to remove the individual sleeve parts, which are only attached at their ends or, in the case of long rotors, in the middle, by loosening a few screws or bolts and to replace them with new or refurbished ones. As can be seen from the invention, it is quite possible to design the composition of the sleeve from several parts differently and, if necessary, to adapt it to the different structural conditions of the rotor. With cast sleeve parts, different favorable dimensions and division levels will result than with a disk rotor, where the division into two half shells is a good option.

Due to the position of the two half shells or the sleeve parts, which should be about 30 - 50 mm thick, a large mass is shifted outwards, giving the rotor a large flywheel mass. This in turn means that the additional flywheels that are otherwise often used for the rotor can be omitted. This not only reduces the cost and increases fatigue strength, but also reduces the cost of repairs and significantly improves puncture resistance.

Claims 3 to 10 define advantageous embodiments of the invention and are understandable from the figure description and drawing.

While in known hammer mills rotor disks and/or arm crosses have to be made of highly wear-resistant, tempered material, with the invention it is now possible to manufacture rotor disks or arm crosses from normal steel. They are protected by the sleeve parts.

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The drawing shows

Figure 1 shows a schematic diagram of a hammer

mill rotor with protective sleeves, Figure 2 is a side view according to Figure 1 .

For example, two end faces 11 and five support disks 17 are attached to the rotor shaft 16 of the rotor 1 of a hammer mill. The end faces 11 and the support disks 17 are provided with holes iö into which the hammer axes 19 are inserted. The hammers 3 are mounted on these so as to rotate freely. Two half-shells 5 are placed over the support disks 17 as wear-resistant sleeves 4 , in which recesses 2 are provided for the hammers 3. Inside the hollow-shaped sleeves 4, rear mounts 13 are welded to both ends, through which the hammer axes 19 are guided. To the left and right of the middle support disk 20 there are fastenings 12 which are formed from lugs 21 and which lock the sleeves 4 against axial play and at the same time prevent them from flying away. Elastic disks 22 are inserted between the rear mounts 13 and the end faces 11, which allow axial movement of the sleeves 4. The rear mounts 13 and the end faces 11 are connected with screws 10. The sleeves 4 are provided with teeth on the parting planes 14 so that they cannot move axially against each other. The two sleeves 4 can optionally be cylindrical or have recesses 6 in the angle area 7 formed by the legs 8 of the cross arms 9. In Figure 2, a star-shaped sleeve 23 with recesses 6 can be seen in the upper half of the rotor 1, while in the lower part the support disks 17 are protected by sleeves 4 above them.

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' 04.07.1985

Reference list

1 rotor 2 Recesses 3 hammer 4 Sleeve 5 Half shells 6 E i. nz ie &eegr;&uacgr;&pgr;^&pgr; 9 &eegr; 7 Angle range 8th leg 9 Arm crosses 10 Screws 11 Front side 12 Fastening 13 Rear facade&eegr; 14 Division level 15 Gearing 16 Rotor shaft 17 Support discs 18 Drilling 19 Hammer axis 20 middle support disc 21 Cleats 22 elastic disc 23 star-shaped sleeve

Claims (10)

P 265 &Lgr; 04.07.1985 \ F~a ten &idiagr;&eegr;&iacgr; nforderungen ! 1. Hammer mill with rotor parts protected against ^wear by protective means, characterized in that the protective means are composed of a multi-part, highly wear-resistant sleeve (4) extending over the length of the rotor (1) and provided with recesses (2) for the hammers (3). 2. Hammer mill according to claim 1, characterized in that | draws net that the sleeve (4) consists of two over f f. the length of the rotor ( 1 ) reaching half-shaft '( len (5). j 3. Hammer mill according to claim 1 and/or 2, \ characterized in that in the cross-section of the sleeve (4) recesses (6) are provided in the angular region (7) between the legs (8) of the arm crosses (9). 4. Hammer mill according to one or more of claims 1 to 3, characterized in that that the fastening elements (screws 10) : Fix the sleeve (4) only radially, but allow axial movement. 5. Hammer mill according to one or more of claims 1 to 4, characterized in that the parts of the sleeve (4) are attached to the rotor (1) only at the end faces (11). 6. Hammer mill according to one or more of the Ahöpfüche 1 to 5, characterized, tj that with very ^long rotors (1) additionally a fastening (12) is made in the longitudinal section, i " 2 - I &bull; I (I &iacgr;I <· II it ··■ I Ii III &igr; · · &igr; . 4 III IIIII t · « * t I t ti I I I I I I l~ III t X III ' _t ; Ii &igr; 7. Hammer mill according to one or more of claims 1 to 6, characterized in that a radial fixing of the sleeve parts to one another and/or to the rotor (1) takes place via rear mounts (13). 8. Hammer mill according to one or more of claims 1 to 7, characterized in that the dividing planes (14) are arranged in the region of the arm crosses (9). 9. Hammer mill according to one or more of claims 1 to 7, characterized in that the dividing planes (14) of the sleeves (4) divide axially into two half-shells (5). 10. Hammer mill according to one or more of claims 1 to 9, characterized in that the dividing planes (14) are formed by toothings (15) or the like. &bull; · < < ti ti 1 III