DE1802377A1 - Magnetic friction apparatus, particularly electromagnetic brake and clutch and its manufacturing process - Google Patents

Description

!;: .-; _: ! -i; ii; ii |! ijii ..:; i! iij || .jj; |;:! - .: iMiij μ » ^^.

Dr. F. Zumstotn - Dr. E. Assmann

Dr. R. Koenia ^ e _t he Dipl. Phys. R. ".. he

Patents

Monks 2, Bräu! .U ", itrai} · 4 / II1

3785-68

CK7TRB irA'i'IOlTAL D3 LA RETURNS SGISiTTIPIQDB

I-'agaet! Frictional apparatus, especially electromagnetic Brake and clutch, and its manufacturing process.

The priority of the French patent application Kr. 124.111 from October 11, 1967 is claimed.

The invention relates to friction apparatus, their

Friction surfaces are pressed against each other by a magnetic effect, especially electromagnetic friction brakes uril clutches

Sofen with known devices of this type m the friction material in terms of consistency with the friction varies in the same sense as the friction surfaces together back compression, satisfactory properties could be given os far var not the same friction material also dt! Krwiinschts to impart magnetic permeability »which allows the friction material in a satisfactory manner at the closure of the

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Magnetic circuit to participate, which the friction surfaces should press against each other »

In any case these were ira general organo-metallic materials which _f of the continuity and the regularity of friction with respect were satisfactory, very sensitive to heat due to the presence of the organic compound, which was a significant disadvantage, in particular when applied to brakes and clutches.

In certain cases it was used as a friction material

in such apparatuses, a ferromagnetic material _Φ used is then which was naturally dia closure of Magnetkreiseg _s the friction surfaces against each other squeezed, but the friction of Weiisisen to "soft iron resulted in a for the continuity W) A, the uniformity of the frictional extremely harmful Pestfressen.

Attempts have also been made to arrange the two materials, namely an organometallic material and a ferromagnetic material, next to one another, which also did not allow a constant, regular friction effect to be achieved, since the two materials do not wear out in the same way, so that earlier or later there was seizure and / or excessive slippage due to melting of the organic compound. Furthermore, when the temperature of these two juxtaposed © M @ a components (the one organic-metallic and the outer ferromagnetic), which "different output coefficients", were in such apparatuses with a temperature increase

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and so have different elongations, the level state of the Friction surface nidifc constant and led to an irregular Work.

The invention aims in particular, the

To remedy the above disadvantages and to make the training so that the friction material not only stable friction properties has, but also contributes to the closure of the magnetic circuit, which seeks to press the friction surfaces against each other, which the Establishing the identity between the friction material and the magnetic circuit allows.

The invention consists essentially in

the friction material by inorganic particles, especially in

for: i or magnetizable

Powders; 'to form au, of which at least some are magnetic, and which are welded to one another on part of their surface, so that a porous, in particular microporous, Structure emerges.

Such a material can be due to its

porous structure does not seize, even if it is in particular the rubbing ^p Smile Friend formed by the poles of an electromagnet directly existing on another homogeneous eg of soft iron.

Due to the presence of magnetic particles in the friction material, it tends to close of the magnetic circuit between the two opposite poles of the electromagnet.

At least certain magnetic particles belonging to the friction material are expediently replaced by alkaline earth metals formed, e.g., yttrium, and / or by rare earths, e.g.

Neodymium, in combination with metals.

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Furthermore, according to the invention, at least certain magnetic particles which form the composition of the friction surface can be formed by double oxides, in particular iron oxide with the oxide of another metal M, ie an oxide of the Fe ₂ OJTCO type, for example a soft ferrite.

Furthermore, certain magnetic particles which form the composition of the friction surface can expediently be formed by Heusler alloys, ie alloys which are magnetic although their individual components are not. Such an alloy is formed by, for example, Ou ₂ , Mn, Al.

The agglomeration of such inorganic particles is expediently carried out either by sintering or by application with the Plasma torch

In this way, the entire anchor can be formed directly with the friction material, but this material can also be used in Form a layer on an anchor from a ferromagnetic Material are applied, which intercept an otherwise possibly dissipating beyond the friction material Auteil of the magnetic flux and can draw conclusions about the poles of the electromagnet.

The magnetic state of the friction material is preferably set or aligned in a magnetic field when it is warm, which corresponds in its direction to that to which the material is later exposed in the electromagnetic rubbing apparatus.

In contrast to other known friction materials, the friction material according to the invention is microporous due to its microporous nature Structure very little sensitive to the presence of lubricants between the two friction surfaces, since

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any lubricant film that is between the two - Seeks to spread friction surfaces, immediately interrupted at the points where the two surfaces come into contact with each other under the magnetic pressure.

The erfindungsgeinässen brakes and clutches can therefore work in a damp environment, especially in Oldanpfen, their An -.-. ^T esQ: unit for the lubrication of certain mechanical

she
Parts of the unit in which / are attached to be desirable

can·

The friction between the two surfaces brought into contact with one another must be even and grow steadily with the pressure, however each partial welding with local tearing off of lights (seizing) or one of the final blocking of the apparatus if Uiiror.c * ü complete accidental welding must be ruled out.

Experiments have shown that one and the same element which crystallizes in two allotropic forms can, namely in hexagonal crystals and in cubic crystals, has the best frictional properties if it is crystallized according to the hexagonal system

To give the friction material the best friction properties ten (uniformity, steadiness with the exclusion of seizure) are preferably at least certain of the inorganic particles entering into the composition of the friction material are selected from those listed in "in the temperatures of use intended for this material have a stable hexagonal crystal structure.

Assuming that in a hexagonal

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Crystal a is the distance between neighboring atoms in the same hexagonal plane and £ the distance between two neighboring atoms Atoms in two neighboring. Is hexagonal planes, that will Networking ratio defined by ~.

If, furthermore, the ideal case is assumed,

in which those going into the composition of the crystal Atoms occupy spheres, it can be demonstrated that for a ideal compact packing of the atoms in the hexagonal crystal applies:

S -ff "1 * 653.

Experiments have shown that the body works with

the best frictional properties, i.e. with the lowest risk of plague eating, are those which are in the form of hexagonal crystals during rubbing,. whose networking relationship is as close as possible to the ideal case for which applies

In the case of many elements that have a hexagonal crystal structure at room temperature, this changes at a certain temperature into a cubic structure, which the friction material adheres to and fulfills its task makes useless.

In accordance with the invention, the constituents of the friction material are selected taking into account the above statements among those which crystallize in hexagonal crystals, and which because of their crosslinking ratio ~, because of their high temperature of allotropic transformation and possibly.

because of their own magnetic properties or because of,

by their presence
those who can leave them / an alloy or a compound,

seem to best "

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Materials of particular interest in this regard are listed in the table below:

Metal ^ temperatures of transformation of the

hexagonal crystals to cubic crystals

417 ⁰ O 33O ⁰ C

chrome 1.62 cobalt 1.624 Lanthanum 1.615 magnesium 1.623 Mqlybdän 1.65 Neodymium 1.612 rhenium 1.615 Samarium 1.610 titanium 1,587 tungsten 1.61 yttrium 1,572

862 ⁰ C

917 ⁰ C 882.5 ⁰ C

construction of

These elements may be on the / Reibmateriala either alone or as alloys, or _t conjunction with either the same table or more arid materials with aluminum,

Copper, iron, kickel, hiobium, with carbides, such as | C Ta, C Ti, C Ko, CW, C ₂ Cr ₃ or with oxides, for example Cr _g O _5, take part.

Cobalt alloys with interesting magnetic and frictional properties are known.

According to the invention, the crosslinking ratio - improved and /

el

or the temperature of the allotropic conversion of the hexagonal crystals into cubic crystals by the addition of Substitution atoms are increased, on which if necessary. A suitable The annealing process follows, which allows the desired hexagonal to be achieved even while working at high temperatures

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To maintain the crystal structure and also to increase the Curie point of the accompanying material thus obtained «.

According to a further characteristic of the invention, in order to improve the frictional properties of the porous friction material, a solid lubricant is incorporated into it, in particular graphite, Mo S ^, Ca P, Ba P, Nb Sg, W Sg ₉ .

In order to accomplish this incorporation of a solid lubricant, the porous friction material of the present invention can be used be impregnated with a suspension of the solid lubricant in a liquid or an epoxy resin in a vacuum »

The invention is explained below by way of example with reference to the reference.

1 shows a schematic axial section of a clutch according to the invention, in particular a brake clutch ;;

Fig. 2 is a schematic axial section a *. ¹ : .2 ³ brake according to the invention »

The coupling shown in Fig. 1 contains a drive shaft 1 and in the extension of the same an output shaft 2 _f on v / which axially a disc 3 connected to the shaft in a rotationally fixed manner can slide.

The preferably made of a ferromagnetic

Material made disc 3 forms the anchor of the electromagnetic Coupling.

The inductor of the coupling is formed by a fixed coil 4 coaxial with axes 1 and 2, which is embedded in a fixed holder 5 made of a ferromagnetic material, which is supported by a radial wall of the Housing of the apparatus can be formed »

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On the drive shaft 1 is an inducing

Rotor attached, aer by two coaxial rings 6 and is formed, which surround the coil 4 inside and outside and with each other by at least one adapter 6 from a non-magnetic material are connected, e.g. made of a light metal alloy ", a rust steel or a brazing alloy

The i'e: th holder 5 forms zv3i e.g. konio ^ io

Surfaces 9 and 10, which within b ;; w. the end ·. : v Coil are lying surfaces of revolution around the shaft 1, and in front of which the rings 6 and 7 rotate with corresponding surfaces, so that during the rotation of the rotor 6, 7 in front of the holder 5, their air gap remains constant and as small as possible.

The rings 6 and 7 also have opposite

the armature 3 two coaxial to the shafts 1 and 2 annular surfaces, which the two poles 11 and 12 of the inducing. Form electromagnets.

The anchor formed by the disc 3 from

ferromagnetic] »material is on its poles 11 and facing surface with a layer 13 aU3 according to the invention Coated friction material, which in particular is immediate on the armature 3 by sintering or by application attach to the plasma torch as described above: H> t ■ :, »

Poles 11 and 12 can also be combined with one be coated according to the invention friction material.

The disc 3 is spread apart from the poles 11 and 12 by a compression spring 14, which between the Disc 3 and the hub 15 of the rotor is arranged, which the rings 6 and 7 belong. The spring 14 thus causes the disengagement of the disk 3 of the rotor 15 »β, 8, 7» so that the

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Wave 2 remains in boo.

When the coil 4 is fed with current,

it creates a magnetic flux in the holder 5 and across the rings 6 and 71 which with their surfaces 11 and 12 respectively attract the disc 3, bi3 their layer 13 against these surfaces lays. The resulting friction between the poles 11 and 12 and the friction material 13 causes the gradual entrainment of the disk 3 until it reaches the rotational speed of the rotor 15 » 6, 8, 7 achieved what the coupling of the WsXIa 2 with the skin 1 is equivalent to.

In numerous cases »especially when the

If the clutch is not to be used in a vehicle, the clutch is generally supplemented by a friction brake, which stops the skins 2 when they are disconnected * should work according to a specific program ^ z »B ₆ machine tools, elevators, household appliances, calculators, brakable motors, etc.

'In this Pail the braking disc 3 can be achieved by one which are gelbildet by the Inneafiache the other radial ¥ ana the housing 17 dea apparatus makes them äwcoh the spring 14 in its disengaged position against a radial! Surface 16 press, canoe."

In addition to this, the seal 3 can be held in the braking position on the plate 1S by permanent magnets 19 built into the housing 17.

Between the clamp 3 and the surface 16 there is preferably a heating material 18 wrapping either with the surface 16 or with the radial surface of the disk 3 ₉

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1862377

which of those carrying the magnetic friction material 13. cr.c ^ e I; c.:; Ü is, is firmly connected.

The Reibnatoriai 18 is also inventive

designed according to the above. Ea can be immediate

even
be applied both to the disk 3 and / to the surface 16, namely by sintering or in the form of a plasma layer.

According to the invention, an electromagnetic brake can also be produced, for example in FIG. 2 shown.

~ o * ^T ince the brake of in shown in Fig. 2

1 has similar components, these are denoted by the same reference numerals followed by the index a ■ *

The one in Pig. Brake illustrated 2 differs "in front" of the coupling shown in Fig. 1 in the '"tual lurch the absence of the shaft 1 and in that d Inge 6a and 7a are fixedly connected to the holder 5JA, and ai> the disk 3a by the Spring 14a is pressed against a shoulder 19 or a stop of the shaft 2a , so that ^ ede brake “. ^ r plate 3 is prevented to the housing 17a when the 3a of the poles 11_a and 12a is spread apart, whereby ^m i "fc a friction material according to the invention may be coated.

When feeding the coil 4a. they pull with electricity Fixed poles 11a and 12a the disc 3a against the action of the spring 14a and brake the rotation of the shaft 2a by friction of the friction lining 13a on the poles 11a and 12a, if necessary * until wave 2a is stopped.

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When the electrical current is interrupted in

of the coil 4a, the spring 14a spreads the Seheibe 3a and thus the Friction lining 13a from the poles 11ji and 12a, whereby the Shaft 2a is released and can rotate freely again.

According to an embodiment modification, not shown, in the same mechanical transmission a electromagnetic clutch according to Pig »1 (but without a brake for the one splayed from the poles 7 and 8 by the spring 14 Disc 3) can be provided in series with the electromagnetic brake according to FIG. The shaft 2a of Fig. 2 is then through the extension of the shaft 2 of FIG. 1 is formed.

According to another embodiment modification, not shown, the in Fig. 1 shown clutch and the brake shown in Fig. 2 are combined.

The disk 3 of the clutch of FIG. 1 may then, in particular instead of the R _e ibmaterials the friction material 18 shown at 13a in Figure 2 bear, and the radial surface 16 may belonging through the poles 11a and 12a of the brake shown in Fig. 2 Electromagnet to be replaced.

With such an arrangement, the springs 14 and 14a can be omitted if the displacement of the disk 3 in the direction of the poles 11 and 12 or the poles 11a and 12a is generated by the alternating excitation of the coil 4 and the coil 4a.

The apparatus according to the invention has numerous advantages, in particular the following:

- it can withstand heating through friction, which is no longer due to the thermal resistance -

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speed of the friction material itself is limited, but only by that of the inducing coil, which can be attached at a certain distance from the surfaces that generate the heating y

- it uses a friction material with better thermal conductivity and through closer contact with the armature, the Hö'glehheit brings the frictional heat from the induction coil through it to keep away that this frictional heat, away from the induction coil directly via the armature, for example through self-ventilation the outer hip can be removed.

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Claims (23)

- 14 - 5785-68 Claims 1 ·) Friction apparatus ι whose guide surfaces are pressed against each other by a magnetic effect »in particular an electromagnetic friction brake or clutch, characterized in that the friction material is formed by inorganic, in particular powdery particles ₉ of which or iragiietizable at least some are magnetic / are, and some on a part so
their surface / are welded to one another »that a porous, in particular microporous, structure is created in such a way that the identity between the friction material and the magnetic circuit can be steepened. 2.) Apparatus according to claim. 1 _f characterized in that at least certain of the magnetic particles entering the composition of the friction surface are alkaline earth metals of the yttrium type « 3 ») Apparatus according to claim 1, characterized in that that at least some of the magnetic particles entering the composition of the friction surface are rare earths are of the neodymium type. 4.) Apparatus according to claim 1, characterized marked t that at least some of the magnetic particles entering the composition of the friction surface are double oxides of iron and another metal M of the type FegO ^ MO ^ in particular are a soft ferrite. 5 β) apparatus according to claim 1 »characterized in that that the friction material contains a Heusler's alloy, i.e. an alloy which is magnetic despite its individual components are not. 909833/0755 - 15 - 3785-68 T 8 O 2 3 7 7 6.) Apparatus according to claim 1, characterized in that the heating material is at least partially through crystalline body is formed, which are selected from those ι which at the normal operating temperatures of the apparatus have and maintain a hexagonal crystal structure. 7.) Apparatus according to claim 6, characterized in that the crystalline. Body, which according to a hexagonal Structure are crystallized, among which are selected their crosslinking ratio - close to the theoretical r - a Fourth ^ l = 1.633. I. 8,) Apparatus according to claim 6, characterized in that that in the friction material at least one component with hexagonal crystals contains substitution atoms which are Netting ratio - approach the value 1.633 el 9.) Apparatus according to claim 6, characterized in that that in the friction material at least one component with hexagonal crystals contains substitution atoms, which its Increase the temperature of the allotropic transformation. 10.) Apparatus according to claim 1, characterized in that | draws that the crystals of at least one magnetic component contain substitution atoms, which is its Curie point raise. 11 ·) Apparatus according to claim 6 and possibly 71 thereby characterized in that the friction material contains at least one of the following elements: chromium, cobalt, lanthanum, Magnesium, molybdenum, rhenium, samarium, titanium, tungsten. 12.) Apparatus according to claim 11, characterized in that the cobalt in the friction material at least one other metal, such as aluminum, chrome, 909833/0755 - 16 - 3785-68 In the form of a r allo ung copper, iron, molybdenum, nickel _f niobium, titanium, tungsten / and / or with a carbide, such as C Ta, 0 Ii, C Mo, 0 W, C ₂ Cr ₅ and / or with an oxide , e.g. Cr ₂ O ^ »is present. 13 *) Apparatus according to claim 1, characterized in that that the crystals of the magnetic components of the friction material in this in the direction of the magnetic field of the domestic. or aligned duct of the apparatus / are set. 14.) Apparatus according to claim 1, characterized in that the friction material is sintered. 15.) Apparatus according to claim 1, characterized in that that the friction material is a plasma overlay. That da3 R _e ibmaterial contains 16 x) apparatus according to claim 1, characterized in that in its pores at least a solid lubricant such as graphite, Mo Sg, CaP, BaP, Nb ₂ S, WS. ₂ 17 ·) A method for producing an apparatus according to at least one of claims 1 to 16, characterized in that that the agglomeration of the inorganic particles takes place by sintering. 18.) A method for producing an apparatus according to at least one of claims 1 to 16, characterized in that that the agglomeration of the inorganic particles is produced by a deposition with the plasma torch. 19.) Manufacturing process according to Claim 17, characterized in that the sintering takes place directly on an anchor made of a ferromagnetic material. 20 ») Manufacturing method according to claim 18, characterized in that the application with the plasma torch look directly at an anchor from a ferromagneti Material made, 909833/0755 - 17 - 3785-68 21 ·) Process for the production of an apparatus • according to claim 6, characterized in that the inorganic Particles of a main ingredient with the glow of an additive be mixed, which in the hexagonal crystals the main ingredient Substitutionsatorae can deliver that then the epidemics of the mixture are agglomerated by sintering or by application with a plasma torch, and that then the sintered body or the support are subjected to an annealing process, which for the diffusion of the atoms ^ of the additive is beneficial in the crystal structure of the main ingredient. 22 ·) Process for the manufacture of an apparatus according to claim 1, characterized in that the magnetic state of the friction material in a warm state in a magnetic field bzt-r aligned
set; hurries / becomes, the direction of which corresponds to that of the magnetic field »to which the material in the apparatus is exposed by the inductor · 23.) A method of manufacturing an apparatus according to claim 16, characterized in that the porous friction material in a vacuum with a suspension of at least one of said solid lubricants in a liquid carrier or is soaked in an epoxy resin. Ö09833 / 0755 ff Empty soap