DE2949040A1 - Friction or bearing layer applied to bore of substrates - esp. where metal bush is lined by centrifugal force and heat with powdered mixts. of metals and/or polymers - Google Patents

Abstract

A rotationally-symmetrical substrate, e.g. a metal bush, is coated in its bore with a rough underlayer. The coated substrate is then heated and rotated while a cold powdered mixt. is fed into the bore and covers the underlayer by centrifugal action to form a friction or bearing layer. The two layers are then compacted by mechanical work. The underlayer is pref. applied by flame- or plasma-spraying, but is esp. a sinter skeleton applied by centrifugal action and sintering immediately before applying layer. Layer is esp. a spheroidal tin-bronze powder; whereas the powder used for layer may be a mixt. of metals and/or polymers, e.g. polyamide and PTFE. A jig is pref. used to rotate bush inside an induction heating coil during deposition of layers. Used esp. to make plain bearings, where the bearing surface is formed by an alloy, e.g. Al-Pb, and/or polymers.

Description

Method and device for applying a friction

or sliding layer on the inner surface of a rotationally symmetrical The invention relates to a method and an apparatus for Application of a friction or sliding layer to the inner surface of a rotationally symmetrical possibly metallic substrate.

It is known to use plain bearings with a high-quality sliding layer made of metallic Suspension alloy, such as aminium-lead suspension alloy, as well Metal-plastic composite bearings of relatively small dimensions are cheaper from strip-shaped Manufacture composite material. So far, however, the qualitative Advantages of those with a sliding layer made of metalliszhev suspension alloy or those Metal-plastic composite layers also for large drive units and bearings, E.g. to use stern tube storage on ships or similar storage locations, because Tape material in the dimensions required for this ~ ~ not Can be produced inexpensively.

It is known that, for example, plastic pipes in steel bushings can shrink, but the resulting shrink fit is not reliable, and during the operation of such composite bearings there are always detachments and this leads to operational disruptions and downtimes.

For the production of large bearings with a high quality sliding layer made of metallic suspension alloy, for example 1 aluminum-lead suspension alloy, So far no satisfactory solutions could be found. Pouring such Suspension alloy in large bearings is out of the question because of the inevitable Segregation during cooling does not result in a uniform composition of the sliding layer can be achieved. The components of suspension alloys, for example, aluminum and lead mix in the mixing ratios to be considered molten state only at very high temperatures.

At low temperatures, the melt breaks down into the Components, for example the two components aluminum and lead. The two-substance system shows a miscibility gap in this area. Due to the big difference in the densities of the two components there is then a very high in the melt rapid segregation and coagulation, so that the use of a plain bearing material required fine distribution, for example fine distribution of the lead in the aluminum matrix cannot be achieved. So far have prefabricated tracks made of metallic suspension alloy only after powder metallurgy Have methods produced.

The object of the invention is therefore to provide a method and a device for the efficient production of large, rotationally symmetrical friction or sliding elements to develop with a suspension-like structure of the friction or sliding layer.

This object is fundamentally achieved with the method according to the invention solved in that a) on the inner surface of the rotationally symmetrical substrate first a rough ground is applied, b) a powdery mixture or suspension precursor of the desired components of the friction or

Sliding layer under rotation and heating of the rotationally symmetrical Substrate is distributed on and in the rough ground and - if necessary - c) the layer formed in this way is mechanically compacted together with the rough ground.

This method can be carried out easily and safely and is guaranteed a uniform composition of the suspension-like friction or sliding layer, because by suitable choice of the rotation speed generated on the substrate Temperatures and the particle fraction of the Structure of the friction or sliding layer used components practically all comparable to Seigern Appearances can be prevented.

The inventive method can also include that the rough ground by flame or plasma spraying or, in particular, as a sintered structure by centrifuging and sintering particles of the rough base material while rotating on the inner surface of the substrate is formed. This means that the formation of the rough ground and the formation of the friction resp.

Sliding layer can then be made to one another and in such a way that the formation of the rough ground by centrifuging and sintering under Rotation immediately before applying the powdery mixture or

Suspension pre-product of the desired components of the friction or Sliding layer is made.

Practically all that can be sintered come to form the rough ground powdery materials into consideration.

In connection with the production of sliding elements one becomes such Choose rough base material, the bearing metal properties, at least good emergency running properties having.

It is special when carrying out the process according to the invention advantageous, an annular substrate element on its end faces by disks to keep, whereby - apart from an inlet for the production of the rough ground and the sliding layer - the end faces of the substrate element locked can be.

Advantageously, the powdery mixture or

Suspension pre-product in for filling the rough ground and forming the friction or sliding layer of the desired thickness according to the measured amount in the one enclosed by the cylindrical substrate element and the front-side disks Cavity can be introduced while maintaining the rotational movement, the substrate element is heated with rotation from its outer circumference.

The mechanical compaction of those formed by spinning with rotation Layer is preferably made in the cold state and can be done by rolling or static compression happen.

For applying a friction or sliding layer made of a metallic suspension alloy In one embodiment of the process according to the invention, a metallic Suspension alloy as a powdered master alloy with preferably spherical grain shape be centrifuged, with a grain fraction between 40 μm and 100 μm, preferably between 60 ym and 100 ym. It is also ! possible in another embodiment, a metallic suspension alloy by intensively mixing powders the Prepare alloy components and apply this powder mixture to the rough ground to be centrifuged, with a grain fraction between 40 μm and 1000 μm, preferably between 60 2m and 100 ym. For producing a friction or sliding layer from plastic particles you can use a powdery plastic mixture, i.e. a mixture that or sliding layer-forming particles on the inner surface of the substrate with rotation fling. Likewise, a powdery one can also be used in the process according to the invention Spin on a plastic-metal mixture or a plastic-metal compound mixture.

But you can also use it in the production of friction or

Sliding layers made from plastic mixtures or plastic-metal mixtures Form a suspension precursor in which the plastic mixture or plastic-metal mixture sintered together or fried and converted back into powder form. This powdery The intermediate suspension product can then be rotated onto the inner surface of the substrate be thrown.

But you can also use a plastic mixture or a plastic-metal mixture for example by means of latent solvents in the form of a pasty suspension precursor bring and this pasty suspension precursor under rotation Apply to the inner surface of the substrate and there for example by evaporation of solvent to stabilize the desired friction or sliding layer.

A particularly advantageous process sequence can take place as follows go: - A cylindrical element forming the substrate is attached to its end faces clamped between two discs and rotating at a precisely determined speed offset; - in those of the rotating disks and the rotating substrate element delimited cavity becomes a measured amount of the rough ground forming, fine-grained Mass, for example tin bronze or lead bronze introduced abruptly; - it will then the cylindrical substrate element precisely from its outer circumference Heated predetermined temperature under protective gas, namely for sintering the rough ground mass suitable temperature; - It will then continue to rotate on the cylindrical Workpiece one for introducing and distributing the mixture or suspension precursor Set the intended temperature and the powdery mixture or suspension precursor in that of the rotating disks and the rotating cylindrical substrate element delimited cavity introduced.

In this case, the rotational speed when introducing can be used in an advantageous manner of the mixture or the suspension precursor into the rough ground through previous Calculate so on the diameter of the substrate element and on the type of Mixture or the suspension alloy are matched that a uniform Distributing takes place while avoiding segregation.

One is particularly suitable for carrying out the method Device based on a known application device a friction or

Sliding layer on the inner surface of the peripheral wall of an annular, possibly metallic substrate, in which a holder receiving the substrate is attached a shaft driven to rotate, one in the space surrounded by the substrate directed material feed and one preferably from the outside onto the substrate Acting heating device are provided. According to the invention at a such device the holding device for the substrate two substantially plate-shaped, have the substrate between them receiving holders that surround the substrate Complete the space at both ends. With these holders a very precise Alignment and balancing of the substrate are done so that the rotation of the substrate equally and thus also the application of the rough ground d the Friction or sliding layer forming materials is perfect and uniform. The heating device can be adapted to the respective type of substrate.

For metallic substrates, for example, gas heating or an induction coil circumferentially surrounding the substrate into consideration. For non-metallic Substrates can, for example, be a high-frequency heating device that surrounds the substrate circumferentially be provided. In any case, the heating device can also be applied to the outer circumferential surface of the substrate have directional infrared emitters, unless the outer circumferential surface of the substrate is designed to be highly reflective.

The material supply primarily has a central inlet channel in at least one shaft part of the holding device, whereby a precisely defined Material input is ensured in the space enclosed by the substrate. It is but also possible, the material supply with at least one centrally in the from Equip substrate surrounding space protruding nozzle arrangement.

For compacting the spun onto the inside of the substrate Layer can be one on the outside and the coated inside of the cylindrical Roll assembly gripping workpiece be provided. But it is also possible for this purpose a press with die-like External tool and Interior work to be provided.

Embodiments of the invention are explained in more detail below. In the drawing: Fig. 1 shows a solid substrate, rough ground and friction or A cylindrical workpiece provided with a sliding layer, for example a plain bearing bush front view, partially cut; Fig. 2 shows a section 2-2 of the FIG. 1 on an enlarged scale; Fig. 3 shows a detail corresponding to Figure 2 for another embodiment of the cylindrical workpiece; 4 shows a detail corresponding to Figure 2; Fig. 5 shows an apparatus for producing workpieces according to Figures 1 to 4, schematically, in vertical section; 6 shows a modified nozzle for use in a device according to Figure 5 in side view; 7 shows a device for compressing the friction or sliding layer applied by centrifugation in one Workpiece according to Figure 1 to 4 by rolling and 8 shows a device for compressing a centrifuged friction or sliding layer in a workpiece according to Figure 1 to 4 by isostatic pressing.

Example 1 One on its inner peripheral surface at 16 (Fiyuren 1 and 2) copper-plated steel bushing 15 forming the substrate is spun open its inner circumferential surface with a sintered frame 14 of substantially spherical Tin-bronze powder beleyt. On the rough ground 14 created in this way, by slinging, i.e. with rotation of the steel bushing 15 a suspension lamination made of aluminum and Lead applied as a sliding layer 13, with the aluminum parts in FIGS at 11 and the lead particles at 12. This suspension alloy essentially has a composition with 80 parts by weight of aluminum and 20 Parts by weight of lead. For this purpose, aluminum powder and lead powder were used accordingly Weight ratio with preferably spherical grain shape and grain fraction between 60, im and 100 / µm mixed together intensively and with rotation on the by heating kept from the outside at a temperature of 4000C, provided with the rough ground 14 Inner surface of the steel sleeve 15 thrown. The speed of the socket was when Spin adjusted so that a speed on the socket inner surface of 85 cm sec 1 eryab.

After the spinning, the steel liner 15 was made by spraying it Outside cooled with water. In the cold state, the composite socket 10 was through Rolling compacted with a reduction in thickness, the rough ground 14 and the centrifuged Layer 13 made of powdery suspension alloy a reduction in thickness of about 55% learned.

B e i s p i e l II In the training shown in Figure 3 is on the inner surface of a bushing made of steel forming the substrate 15 is the rough ground 14 formed by mechanical roughening. On this rough base 14 is a sliding layer 13 applied, which has a matrix 21 made of polyvinylidene fluoride. In this Matrix 21 are finely dispersed PTFE particles 22 evenly distributed. The maximum The diameter of these PTFE particles 22 is 0.1 μm to 5 μm. Likewise is in the matrix 21 an additional material 23 is embedded, which has a density of> 8gr / cm3, with a grain fraction <40 cm.

Friction layer is about 200 µm.

A Ssaspension pre-product of 65% by volume is used as the coating material. Polyvinylidene fluoride (PVDF) 26% by volume lead, lead oxide, lead sulfide, grain fraction £ 40 ym 10 vol .-% low molecular weight polytetrafluoroethylene (PTFE), particle size 0.1 to 5 ym made.

For this purpose, the PVDF is dissolved in a latent solvent and in the other components are added to a high-speed stirrer. As the cheapest Viscosity for centrifuging into the rotationally symmetrical substrate 15 has a Outflow time according to Engler between 60 to 80 seconds.

To produce the layer material, this was done beforehand on the inner surface to form the rough ground 14 mechanically roughened and on the rotating device attached annular substrate 15 heated to a temperature of 2800C and a defined amount of the inventive coating compound in the opening of the rotationally symmetrical Substrate 15 coated evenly. It has been found to be most beneficial for a rotationally symmetrical Body with an inner diameter of 300 mm a rotation with speed between 55 and 60 min 1 proved, since at the corresponding peripheral speed between 80 to 100 sec 1 no segregation of the additives takes place and due to the centrifugal force, the additive also affects the fluoropolymer matrix 21 presses so that an excellent bond under the action of a targeted Cooling of the Fbiorpolymer to the substrate 15 is achieved.

Following the application and solidification of the coating and targeted cooling, the friction or

Sliding layer 13 no longer compacted.

Instead of producing a pasty suspension preliminary product, in this example with the same composition, but omitting the latent Solvent a powdery mixture of the desired ingredients for the friction or Glitschicht introduced into the space surrounded by the rotating substrate bushing will. It then takes place on the heated inner surface of the substrate socket or the sintering between the particles occurs on their mechanically formed rough ground 14 of the powder mixture.

It is also under the composition given in this example possible to first sinter the powder mixture together and, if necessary, to compress and then to to grind a powdery suspension precursor, then in the manner described above into the space within the rotating substrate bushing 15 is introduced.

Example III: In the example shown in FIG. 4, the at 16 copper-plated inner surface of a steel bushing 15 serving as a substrate Rough base 14 in the form of a sintered structure made of tin bronze or lead bronze, practically in the same way as in Example I.

In this example, a powdery mixture of polyamide 11, Lead with about 0.5% tin content to increase corrosion resistance and low molecular weight PTFE in the interior of the rotating and heated substrate bushing after construction of the rough ground 14 introduced.

Instead of or in addition to the lead, other metals are also used, like copper, bronze, into consideration. In the present example, the powdery Mixture of the following composition: 15% by volume lead with 0.5% tin content with particle size <40 µm, 1.5 vol. Low molecular weight PTFE with particle size between 4 and 6 Cm, remainder polyamide 11 with particle size c 40 cm.

When introducing this powder mixture into the interior of the substrate socket 15 and in the resulting formation of the friction or sliding layer 13 the substrate socket is heated from the outside to such a temperature that the Melting temperature of the polyamide 11, but below the decomposition temperature of the plastic contained in the powder mixture. After the entire stipulated Amount of the powdery mixture introduced and the resulting friction or Sliding layer on the inner surface of the substrate bushing 15 or the one attached there Rough base 14 has melted, the substrate bushing 15 is slowly cooled from the outside, up to a temperature of 2000C. By melting the powdery mixture and the slow cooling with rotation will already result in a high density of friction respectively.

Sliding layer 13 reached. However, it is recommended to do this too In the case of the friction or sliding layer additionally by rolling or isostatic pressing to condense.

Tests have shown that by adding the lead to the polyamide 11 whose viscosity in the melt is increased so much that the in Figure 4, lead particles shown at 26 do not segregate under the action of centrifugal force but just like the fine PTFE particles shown at 25 finely dispersed in the Plastic matrix 24 remains distributed. With the slow one cooling down the finely dispersed storage of the lead particles offers the advantage of being completely more even Cooling of the matrix plastic 24 and thus achievement of a high degree of crystallinity and only low internal stresses in the matrix 24.

The layer thickness can, for example, only be between 0.07 mm and 0.2 In all three examples, the basic order is the Method steps according to the invention as follows: The rotationally symmetrical substrate 15, for example a steel bushing or other cylindrical metallic substrate element, is clamped in a jig 30, which is fixed to the horizontal or vertical standing centrifugal axis of a drive unit is connected. The jig 30 is provided with a front and a rear cover plate or sealing plate 31, 32 made of metal. The cover or sealing plates 31, 32 are on their surface provided with a non-stick layer.

A filling funnel leads through the front cover or sealing plate 31, whose task it is to produce the mixture or dispersion precursor used for the spin coating to the r <, cation-symmetrical substrate 15 to- to lead. This The substrate is heated from the outside and via the drive unit brought to the selected rotation speed. After reaching the chosen The mixture or the operating data is fed via an automatic metering device 40 The intermediate suspension product is fed to the rotating substrate 15 and utilized the centrifugal force and temperature firmly on its surface, i.e. the ones arranged there Rauhgrund 14 bound.

By varying the temperature and the speed of rotation, a smooth, closed or even a microporous tear or sliding layer produced will.

In the latter case, the porosity can be useful as a lubricant reservoir be used.

In the device shown in Figure 5, the sleeve-shaped substrate 15 between the two cover and sealing plates 31 which are conically formed there and 32 mounted rotatably in bearings 35 and 36, respectively. A drive gear 37 supplies the cover and sealing plate 32 with the rotary movement. An induction coil 38 surrounds the substrate 15. Instead, however, a high-frequency heating coil can also be used or an infrared heater arrangement can be provided.

A nozzle 33 extends through the cover; Ind sealing plate 32, which in this case is designed to be a tin bronze powder or a powder mixture of tin bronze and tin. The one generated on the substrate by the rotation Centrifuge effect has the consequence that the tin bronze powder evenly on the Inside of the substrate socket 15 is distributed, after which it is passed through by the coil 38 generated heat is sintered or melted. It becomes a porous one there Rough ground created as a preparation for the introduction of the friction or sliding layer forming mixture or suspension precursor.

A nozzle 34 extends through the cover or sealing plate 31 and becomes with the mixture or suspension precursor that forms the friction or sliding layer loaded. This mixture is fed from a funnel or storage container 41 transferred to a measuring and allocating device 42. From there the measured Amount of suspension precursor by means of a protective gas flow (such as through the feed line 43 and the injector 44 indicated) ggi. puff-like or jerky in the Substrate socket 15 and surrounded by the cover and sealing plates 31 and 32 Encouraged interior space closed at both ends. The coating then takes place on the inner surface of the substrate socket 15 on the there previously attached RauhyruPd 14 using centrifugal forces corresponding to those on the substrate socket set rotation speed. As a result of the simultaneous heating effect The applied mixture or suspension precursor is welded by the coil 38 or melted or

stabilized from viscous state to solid state, for example by evaporation of solvent.

If it is desired to process viscous suspension preproducts, which contain solvents can be used instead of the introduction nozzle shown in FIG 34 a nozzle 50 shown in Figure 6 can be used. This nozzle 50 has on her Nozzle tube 51 a number of separate, essentially radially directed nozzles 52, which are shown in Figure 5 for the sake of simplicity only in one row. Instead of this can also have several rows of such individual nozzles 52 on the circumference of the nozzle tube 51 be arranged.

After coating the inner surface of the substrate socket 15 and the Stabilize this layer by sintering, welding or evaporation Solvent, the friction or sliding layer produced can be compacted. For this FIG. 7 shows a roller arrangement 60 with an inner roller 61 and an outer one Hollow roller 62, the latter being the cylindrical workpiece 10 to be treated records and is itself supported by smaller carrier rollers 63. The drive can be from the Inner roller 61 take place here or by the support roller 63 over the outer roller 62. This additional rolling causes the particles in the suspension of the sliding or friction layer firmly pressed together and pressed into the rough ground, whereby eire Compaction of both the friction layer and the rough ground occurs. If desired, this rolling can be done with controlled heat input.

For this purpose, additional heating devices 64 are shown in FIG act on the down roller 62.

FIG. 8 shows a device 70 for compacting the in the substrate socket formed coating by means of isostatic pressure. To this end, the facility 70 a die-like receiving tool 71 with a part-cylindrical receptacle 72, which is the outer surface of the cylindrical Who! piece corresponds to 10. A pressure piece or punch 73 engages the inside of the lined workpiece 10 in order to exert controlled, predetermined pressure on them. This will make the the suspension forming the layer is compressed and pressed into the rough ground. The device according to FIG. 8 naturally requires several printing processes with intermittent printing Turning the workpiece 10.

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Claims (31)

Claims 1) Method for applying a friction or sliding layer on the inner surface of the peripheral wall of a rotationally symmetrical, possibly metallic Substrate, characterized by the steps: a) on the inner surface of the rotationally symmetrical A rough ground is applied to the substrate; b) a cold and powdery one Mixture or suspension precursor of the desired components of the friction or sliding layer is produced by spinning while rotating and heating the rotationally symmetrical substrate and distributed in the Rauhytund; c) by spinning with rotation from the mixture or the suspension precursor layer formed on the inside of the substrate is mechanically compacted together with the rough ground. 2) Method according to claim 1, characterized in that the rough ground by flame or plasma spraying or, in particular, as a sintered structure by centrifugation and sintering particles of the rough base material while rotating on the inner surface of the substrate is formed. 3) Method according to claim 2, characterized in that that the formation of the rough round by centrifuging and sintering with rotation is immediate before the powdery mixture or suspension precursor is applied desired components of the friction or sliding layer is formed. 4) Method according to claim 2 or 3, characterized in that the Sintered structure is formed from essentially spherical tin-bronze powder. 5) Method according to one of claims 1 to 4, characterized in that that a rotationally symmetrical substrate element on its end faces by discs held and - apart from an inlet for the production of the rough ground and the Sliding layer - closed and rotating by a drive unit is moved. 6) Method according to claim 5, characterized in that the powdery Mixture or suspension precursor in for filling the rough ground and forming it the friction or sliding layer of the desired thickness according to the measured amount in those enclosed by the cylindrical substrate element and the face-side disks Cavity is introduced while maintaining the rotational movement. 7) Method according to claim 6, characterized in that the substrate element is heated under rotation from its outer circumference. 8) Method according to one of claims 1 to 7, characterized in that that the mechanical compression of the centrifugal on the inside of the rotationally symmetrical Substrate attached friction or sliding layer is made in the cold state. 9) Method according to claim 8, characterized in that the mechanical Compaction of the on the inner surface of the rotationally symmetrical substrate by centrifugation applied friction or sliding layer made by rolling or static pressing will. 10) Method according to one of claims 1 to 9, characterized in that that a metallic suspension alloy as a powdered master alloy with preferably Kuqeliger grain shape is centrifuged, with a grain fraction between 40 and 1000 µm, preferably between 60 µm and 100 µm. 11) Method according to one of claims 1 to 9, characterized in that that a metallic suspension alloy by intensive mixing of powders of the Alloy components prepared and this powder mixture thrown onto the rough ground is, with a grain fraction between 40 μm and 1000 m, preferably between 60 around 100 yn 12) Method according to one of claims 1 to 11, characterized in that that a sliding layer made of a suspension alloy with the main components Aluminum and lead, preferably essentially 80% by weight aluminum and 20% by weight. Lead built up by spinning on the inside of the rotationally symmetrical substrate will. 13) Method according to one of claims 1 to 12, characterized in that that the substrate with the rough ground and the powder layer thrown on at one temperature between 330 and 5500C and a degree of deformation between 30% and 60%, preferably between 50% and 60%, rolled together or statically pressed together will. 14) Method according to one of claims 1 to 7, characterized in that that a friction or sliding layer made of a powdered plastic mixture through Spin onto the inside of a rotationally symmetrical substrate while rotating is being built. 15) Method according to one of claims 1 to 7, characterized in that that a friction or sliding layer made of a powdery plastic-metal mixture by spinning on the inside of a rotationally symmetrical substrate Rotation is built up. 16) Method according to claim 15, characterized in that the plastic-metal mixture contains powdered polyamide 11 and powdered metal such as copper, bronze, lead. 17) Method according to claim 16, characterized in that the powdery Plastic-metal mixture contains: 5 to 20% by volume, preferably 10 to 15% by volume of lead and 0.02 to 2, preferably 0.5; Tin content and small size SM0 cm 0 Up to 3% by volume of low molecular weight PTFE with a particle press between 2 and 8 μm, preferred between 4 and 6 μm, the remainder being polyamide 11 with a particle size of 5 40 μm. 18) Method according to one of claims 1 to 7, characterized in that that a friction or sliding layer made of a viscous suspension precursor through Filling or injection of this suspension precursor into the from the substrate surrounding space is built. 19) Method according to claim 18, characterized in that the suspension precursor sprayed onto the inner surface of the heated rotating substrate. 20) Method according to claim 1, characterized in that - an im essentially only formed by the substrate, cylindrical element on its End faces clamped between two disks and in a rotation with exactly predetermined Speed is offset, - in that of the rotating disks and the rotating Substrate element umyrenzten cavity forming a measured merge of the rough ground fine-grained mass, for example tin bronze. or lead bronze is suddenly introduced, - then the cylindrical substrate element from its outer circumference to a precisely predetermined one Temperature is heated and that temperature suitable for fritting the Rauhgrund mass and then one for the introduction of the cylindrical workpiece, which continues to rotate and distributing the mixture or suspension precursor at the intended temperature set and the powdery mixture or suspension precursor in the of the rotating disks and the rotating cylindrical substrate element Cavity is introduced. 21) Method according to claim 1, characterized in that the rotational speed when introducing the suspension alloy into the rough ground by calculating beforehand such on the diameter of the substrate element and on the type of the to be built up Layer contained suspension is adjusted so that an even distribution takes place while avoiding segregation of the suspension. 22) Method according to claim 21, characterized in that at one rotationally symmetrical substrate with an inner diameter of 300 mm and a The friction or sliding layer to be built up, the additives 3 of which have a density of '8 g / cm a rotational speed at -l 55 to 60 min. 1 is provided. 23) Device for applying a friction or sliding layer to the Inner surface of the rotationally symmetrical peripheral wall of an optionally metallic, tubular Substrate in the method according to one of Claims 1 to 22, in which one is the substrate receiving bracket on a shaft driven to rotate, one in the Material feed directed from the space surrounding the substrate and preferably one heating devices acting on the substrate from the outside are provided, characterized in that the holding device for the substrate (15) consists of two essentially plate-shaped holders which receive the substrate (15) between them (31, 32) consists of the space surrounded by the substrate (15) on both end faces to lock. 24) Apparatus according to claim 23, characterized in that the Heating device for metallic substrates surrounding the substrate (15) circumferentially Induction coil (38) or a gas burner. 25) Apparatus according to claim 23, characterized in that the A heating device for non-metallic substrates encompassing the substrate circumferentially High frequency heating device is. 26) Device according to one of claims 23 to 25, characterized in that that the heater is directed towards the outer peripheral surface of the substrate (15) Has infrared emitters. 27) Device according to one of claims 23 to 26, characterized in that that the material feed a central inlet channel on at least one shaft part (33, 34) of the holding device. 28) Device according to one of claims 23 to 27, characterized in that that the material feed at least one centrally in the one surrounded by the substrate (15) Has a space projecting nozzle arrangement (50, 51, 52). 29) Device according to one of claims 23 to 28, characterized in that that one on the outside and the coated inside of the cylindrical workpiece (10) gripping roller assembly for compacting on the inside of the substrate (15) spin-on layer is provided. 30) Apparatus according to claim 29, characterized in that a outer hollow roller (62) for receiving the workpiece (10) and provided by a Number of carrier rollers (63) is supported and driven. 31) Device according to one of claims 23 to 28, characterized in that that a press with die-like outer tool (71) and inner tool (73) for Compress the centrifuged onto the inside of the coated workpiece (10) Layer is provided.