DE102010055178A1 - Sealed bearing arrangement for use in tribological system, has sealing rings provided with aperture at radial height of volume part, where aperture is semipermeably closed by breathing elastomer membrane and forms gas passage - Google Patents

Abstract

The arrangement (1) has a seal device (6) comprising circular sealing rings at axial ends of bearing rings (31, 32). The sealing rings are made from an elastomeric material and include outer and inner circumferences. An annular space (50) comprises a free volume part (51), and is located among the bearing rings and the equipped sealing rings. The sealing rings are provided with an aperture (72) at radial height of the volume part. The aperture is semipermeably closed by a breathing elastomer membrane and forms a gas passage. A carrier for the membrane is made of metal or plastic.

Description

The invention relates to a sealed bearing assembly with a semi-permeable elastomeric membrane - in particular a sealed rolling bearing with a closed by a semipermeable elastomer membrane free volume.

Bearing arrangements are machine elements in a tribological system, which move moving parts in a certain place or on a given railway line and have to cope with the occurring forces; are addressed sliding bearings and preferably rolling bearings, as here the presented problem solving attacks more. Rolling bearings - as well as bearings - transfer forces between relative moving machine parts and lead them. By interposing rolling elements, the sliding is replaced by a roller with a small sliding portion - the rolling.

In all rolling bearings are spherical or roller-shaped rolling elements - such as ball (ball bearings) or cylindrical roller, needle roller, tapered roller or spherical roller (roller bearings) - mostly guided by a cage on careers high strength, surface quality and dimensional accuracy, in the inner ring and the Outer ring of the bearing or incorporated in the subsequent components.

Deep groove ball bearings are the most versatile, since they are particularly inexpensive to produce and readily available, as individual bearings can absorb both radial and axial forces in both directions, can have high speeds with low noise, make low demands on the lubrication and stress the lubricant little. Deep groove ball bearings are also produced in large quantities as greased and sealed units. The standard version has no filling grooves and therefore has the same axial load capacity on both sides, but with fewer balls. It also absorbs low tilting moments; For high radial loads there are double row bearings. Deep groove ball bearings can not be dismantled.

Ball and roller bearings are differentiated according to their Wälzkörpergeometrie. Rollers can be shaped as cylinder sections, as truncated cones or as symmetrical or asymmetrical barrels with a circular arc profile. In the unloaded condition results in a line contact for the roller bearing, while the ball bearing - since the ball radius is smaller than the Laufbahnkrümmungsradien - has a point contact. As a result of larger contact surfaces under load due to elastic deformation roller bearings take on the same material stress higher forces. In order to reduce the unavoidable stress peaks at the ends, cylindrical rollers received spherical transition zones towards the end surfaces; Today, slightly convex logarithmic profiles are preferred for cylindrical and tapered rollers. Spherical rollers - similar to ball bearings - have a slightly smaller radius of curvature than their raceways. Since roles other than balls have a defined axis of rotation, a skew must be prevented by measures. Casters are guided between two ribs with play - Cylindrical roller bearings - on a fixed board or on a loose guide ring with tension guide - Tapered roller bearings, spherical roller bearings - mainly by the cage - Needle roller bearings - or by friction forces between rollers and raceways - Spherical roller bearings, Toroidal bearings.

• – rotierende Bewegungen
• – ausschließlich oder überwiegend radiale Belastung
• – ausschließlich oder überwiegend axiale Belastung
• – radiale und axiale Belastungen-Schräglager
• – lineare Bewegungen.

Rolling bearings are differentiated according to types in stock for

• - rotating movements
• - exclusively or predominantly radial load
• - exclusively or predominantly axial load
• - radial and axial loads-angular contact bearings
• - linear movements.

• – Weiterleitung von Massen- und Schlupfkräften
• – Verhinderung der unmittelbaren Berührung von Wälzkörpern
• – gleichmäßige Verteilung der Wälzkörper bei teilgefüllten Lagern – Rillenkugellager
• – Führung von Wälzkörpern.

Rolling bearing cages have different tasks depending on the type of bearing

• - Forwarding of mass and slip forces
• - Preventing the direct contact of rolling elements
• - even distribution of the rolling elements in partially filled bearings - deep groove ball bearings
• - Guide of rolling elements.

Bearing arrangements - of whatever kind - include not only the bearings, but also the immediately adjacent components. In addition to shafts and housings, especially gaskets whose function is of crucial importance for the cleanliness of the lubricant, which has an effect on the fatigue life. Bearing arrangement and sealing are to be understood as a system; the design of the seal and the choice of seal determine the desired life. Rolling bearings must be protected against the penetration of solid and liquid contaminants, otherwise there is a risk of corrosion, wear and no permanent rolling resistance. Active sealing elements are therefore preferably used to promote grease lubrication to the outside; while the accumulation of non-contacting sealing parts is sufficient to keep enough lubricant in the camp. Often, non-contact seals are sufficient; more effective are touching seals, preferably with an upstream labyrinth.

In case of oil lubrication, the oil should be kept in the bearing housing; What is required are active sealing elements that promote the interior. Depending on the oil level in the camp also labyrinth seals or contacting seals, such as additional seals or additional outer protective lips, which contain a sealing grease reservoir in their pronounced chambers.

Contact seals are felt rings, radial shaft seals, sealing washers and mechanical seals of different or composite materials with and without outer sealing lips. They work wear-free after a running-in period, as long as there is microelastohydrodynamic lubrication and the material does not age or the contact surfaces are damaged by the formation of carbon deposits. Commonly used are metal-reinforced sealing disks with sealing lips made of nitrite-butadiene rubbers (NBR), fluorinated rubbers (FKM) or polytetrafluoroethylene (PTFE); the degradation of the contact pressure by permanent change in shape can be counteracted by the use of metal springs.

Non-contact seals are integrated cover plates, outer labyrinths, Z-lamellae and spring-loaded sealing washers - Nilos rings are non-contact after running-in wear; they allow higher speeds because of the lower friction losses. Outer labyrinths, Z-lamellas and radial shaft seals actively convey inward or outward depending on installation direction - pumping direction from small to large contact angle.

• – Verhinderung oder Verminderung von Verschleiß an Kontaktgleitstellen
• – Abbau von Spannungsspitzen und Reibungsschubspannungen an der Oberfläche der Wälzkontakte
• – Korrosionsschutz
• – Kühlung, in dem Öle die Abfuhr von Verlustleistung aus dem Lager bei ausreichender Durchströmung unterstützen.

The rolling bearing lubrication by greases, oils and solid lubricants fulfill the tasks in the rolling bearing

• - Prevention or reduction of wear at contact sliding points
• - Reduction of voltage peaks and Reibungsschubspannungen on the surface of the rolling contacts
• - corrosion protection
• - Cooling, in the oils support the dissipation of power loss from the camp with sufficient flow.

Prerequisite for the fulfillment of the first two tasks is the separation of the metallic surfaces by a hydrodynamic liquid film or a protective reaction layer. In hydrodynamic film formation, the elastic deformations are essential for point and line contact - called elastohydrodynamic lubrication. The lubricant film formation must exceed the surface roughness and is dependent on operating temperature, pressure and kinematic viscosity of the lubricant.

• – Betriebsbedingungen
• – Forderungen an Laufeigenschaften
• – Einbauverhältnissen
• – Wartung
• – Umweltverhältnisse

abhängig, wie bei

• – einer Spritzwasserumgebung der Einsatz von wasserabweisendem Fett wie Kalziumseifenfett und bei
• – einer Kondenswasserbildung der Einsatz von emulgierendem Fett wie Natron- oder Lithiumseifenfett

sinnvoll erscheint, wobei die Verträglichkeit bei Mischverhältnissen zu prüfen ist. Fette verlieren ihre Gebrauchseigenschaften über die Zeit, die von den physikalischchemischen Fetteigenschaften, der Lagerbauart, der Drehzahl und der Temperatur abhängt – Fettwechsel oder Nachschmieren muß nach festgelegten Fristen erfolgen. Bei Neubefettung oder einem Fettwechsel empfiehlt unter Berücksichtigung von Gebrauchsdauer und Reibung eine Füllmenge von ca. 30% des nicht von bewegten Teilen überstrichenen freien Volumens für mittlere Drehzahlen (bei niedrigen Drehzahlen mehr, bei höheren weniger Füllmenge). Kann das überschüssige Fett in seitliche Freiräume ausweichen, stellt sich bei Betrieb im Lagerinnern drehzahlabhängig die notwendige Fettmenge selbsttätig ein.Greases are solid or semi-liquid products of a dispersion of a thickening substance in a liquid lubricant. By delivering a sufficient amount of liquid lubricant through slow separation, they are designed to prevent friction and wear over wide temperature ranges and over long periods of time. At the same time they serve to seal against water and foreign particles. Fats consist of metal and alkali soaps as thickeners - which also serves as an oil reservoir - and a base oil. Grease lubrication is the standard solution for most of all rolling bearing applications - a minimum quantity lubrication with very low friction losses. The fat selection is of different criteria like

• - Operating conditions
• - Requirements for running properties
• - Installation conditions
• - Maintenance
• - environmental conditions

depending on how

• - a spray water environment the use of water-repellent grease such as calcium soap grease and at
• - the formation of condensation water, the use of emulsifying fat such as sodium or lithium soap grease

makes sense, with compatibility in mixed ratios to check. Greases lose their performance properties over time, depending on the physico-chemical properties of the grease, the type of bearing, the speed and the temperature - grease change or relubrication must take place after specified periods. For new grease or a grease change, taking into account the service life and friction, a filling quantity of approx. 30% of the free volume not swept by moving parts is recommended for medium speeds (at lower speeds more, at higher, lower filling quantities). If the excess grease can escape into lateral clearances, the necessary amount of grease automatically sets itself up when operating inside the bearing, depending on the speed.

• – die – im wesentlichen – Wälzlager nach Befettung ein nicht von bewegten Teilen überstrichenes freies Volumen von ca. 70% aufweisen,
• – sich in dem Volumen anwendungsbezogen Kondenswasser bildet und
• – versucht wird, durch Einsatz emulgierender Fette wie Natron- oder Lithiumseifenfett der Kondenswasserbildung durch Wasseraufnahme entgegenzuwirken. Der Einsatz von wasserabweisendem Fett wie Kalziumseifenfett – zu prüfen ist noch die Verträglichkeit mit anderen Fettsorten – schützt bei guter Fettung zwar vorübergehend die sich relativ zueinander bewegenden Teile der Lageranordnung vor eingedrungenem Wasser, jedoch befindet sich das Medium noch in dem oben dargestellten freien Volumen des dichten Lagers und wird wegen Nichtaustritt einen Beitrag zur vorzeitigen Korrosion und Zerstörung des Lagers leisten.

In summary, it is stated that

• - have the - substantially - rolling bearings after lubrication a not swept by moving parts free volume of about 70%,
• - Condensation forms in the volume depending on the application and
• - It is attempted to counteract the formation of condensation by the absorption of water by using emulsifying fats such as sodium or lithium soap fat. The use of water-repellent grease such as calcium soap grease - to check is still the compatibility with other grease - protects with good greasing while temporarily moving relative to each other parts of the bearing assembly from water penetration, however, the medium is still in the above-described free volume of dense Lagers and will contribute to the premature corrosion and destruction of the camp because of non-leakage.

According to an advantageous embodiment of the inventive novelty is therefore proposed to open the bearing assembly - based on the currently sealed free volume - semi-permeable means of a membrane - ie the membrane is for liquid media - such as spray - an absolute barrier and leaves substances in gaseous state - As condensation as humid air - happen - so as to escape - as well as any formed - trapped in the free volume of the bearing liquids in the gaseous state.

The elastomeric membrane of the inventive novelty is preferably made of a rubber material - such. B. silicone rubber - with good gas and water vapor transmission rates, which is processed in 2K or 3K (component) -Spritzverfahren directly with a venting element to a ventilation valve. Due to a required shape of the elastomeric membrane and the Shore hardness of the material, it is necessary to use a z. B. finger-like / star-shaped or annular carrier, which is encapsulated as a stock or insert with the rubber material.

All plastic materials are very or slightly permeable to gases, vapors or liquids; the permeability is also referred to as permeation or permeability, the crude solution or the feed is fed to the membrane, through the membrane passes the concentrate or the permeate, the different residual amount of crude solution and concentrate is the retentate. Particularly important are the permeability to water vapor, gases and vapors for liquids. High or low permeabilities of plastic films / membranes for certain substances may be required or undesirable depending on the field of application.

• – für die Gasdurchlässigkeit ca. 600 cm³ × mm/(m² × h × bar); d. h. Menge Luft, gemessen in cm³, die pro Stunde bei einer Druckdifferenz von 1 bar eine Membran von 1 m² Fläche und 1 mm Dicke durchdringt
• – für die Wasserdampfdurchlässigkeit ca. 40 g × mm/(m² × d); d. h. Masse Wasserdampf in g, die in 24 Stunden eine Membran von 1 m² Fläche und 1 mm Dicke durchdringt.

According to the present inventive novelty to the water air - consisting essentially of about 78% nitrogen (N2), about 21% oxygen (O ₂ ) and about 0.04% carbon dioxide (CO ₂ ) and water vapor, measured in relative Humidity - be removed; the relation of the passage for plastics for N ₂ : O ₂ : CO ₂ is about 1: 4:16. Another example relates to the permeability of water vapor to prevent condensation in housings tax and control systems. In almost all plastic films - with the exception of cellulose hydrate (CH), trade name cellophane or cellophane - the permeability decreases with the thickness. The membrane permeability of gas is determined according to the test standard DIN 53 380 in the unit [cm ³ / m ² × d × bar] and that of water vapor according to test standard DIN 53 122 in units of [g / m ² × d]. Magnitudes are for rubber, 50 Shore Hard, 20 ° C temperature

• - for the gas permeability about 600 cm ³ × mm / (m ² × h × bar); ie amount of air, measured in cm ³ , which per hour penetrates a membrane of 1 m ² area and 1 mm thickness at a pressure difference of 1 bar
• - For the water vapor permeability about 40 g × mm / (m ² × d); ie mass of water vapor in g, which penetrates a membrane of 1 m ² area and 1 mm thickness in 24 hours.

Hydrophobic plastics absorb no water vapor, so there is no influence on the gas permeation; Hydrophilic plastics can absorb significant amounts of water vapor, which increases the size of the gas passage.

• 1. Durchgang durch porenfreie Kunststoffschichten infolge Lösungsdiffusion bei a) und b) außerhalb der Poren im die Poren umschließenden Kunststoff (Permeation, Normalfall)
• 2. Durchgang durch größere Poren und Fehlstellen infolge Fick'scher Diffusion a) wobei die Poren die gesamte Membrandicke durchdringen, wie offenporiger Schaum oder Perforierungen oder poröse Membranen b) wobei die Poren sich innerhalb der Membran befinden, wie geschlossenporiger Schaum oder poröse Membranen (Durchmesser der Poren > freie Weglänge der Gasmoleküle)
• 3. Durchgang durch Mikroporen infolge Knudsen-Diffusion a) wie bei mikroporösen Membranen b) in den eingeschlossenen Poren wie bei mikroporösen Membranen (Porendurchmesser < freie Weglänge der Gasmoleküle)

At the same total pressure inside and outside of two membrane-separated spaces, three gas passage mechanisms can be described by plastics, such as

• 1. Passage through pore-free plastic layers due to solution diffusion in a) and b) outside the pores in the plastic surrounding the pores (permeation, normal case)
• 2. Passage through larger pores and voids due to Fick's diffusion a) where the pores penetrate the entire membrane thickness, such as open cell foam or perforations or porous membranes b) where the pores are within the membrane, such as closed cell foam or porous membranes (diameter the pores> free path of the gas molecules)
• 3. Passage through micropores due to Knudsen diffusion a) as in the case of microporous membranes b) in the enclosed pores as in microporous membranes (pore diameter <free path of the gas molecules)

At total pressure difference between the rooms is a
to 1. the solution diffusion
to 2. a Poiseuille flow in place of Fick's diffusion; leads to pressure equalization (DA) in a relatively short time (seconds to days)
to 3. the Knudsen diffusion.

The gas diffusion during passage through micropores is not temperature dependent.

The passage mechanisms for water vapor correspond to those of the gas passage. At very high water contents can also occur in the pores because of capillary condensation Kapillarwasserzug as a transport mechanism. In solution diffusion as gases pass, the gas passage increases linearly with the gas Partialdruckunterschied of the continuous gas, which does not apply due to the non-linear with the partial pressure of the water vapor increasing sorption of elastomeric membranes in water vapor; a linear conversion at the driving gradient of the water vapor partial pressure - or the relative humidity - is not permitted.

In addition to a fairly crude mechanical perforation, the laser technology offers the possibility of conferring a microperforation of a film or a membrane that is specifically adapted to the respective application purpose. The hole size and the number of holes is dimensioned so that air circulation is possible, but moisture is retained. Other methods are needle technology and flame perforation. The laser is characterized by smaller holes, which are tear-proof by a micro-melt edge. In addition, the laser operates contactless and process-safe at high web speeds, against the risk of breakage in needles.

A change in the relation of the gas passage is only possible by introducing pores in the films / membranes and to be able to influence the patency targeted, both in terms of volume and in the ratio of gases with each other. The permeability is composed of the solution diffusion of the film / membrane and the Fick'schen or Knudsen diffusion of the micropores and the total passage and the relation of the passages are determined by a targeted selection of both influences. Microperforation can be achieved by mixing in fine mineral fillers with molecular diffusion channels in the particle or at the particle / plastic contact point, which can also be influenced by stretching the film (controlled atmosphere packaging - Controlled Atmosphere Package [CAP] / Housing). CAH]).

In the following, the prior art of sealed bearings with a semi-permeable elastomer membrane - especially sealed sealed bearings with a closed by a semi-permeable elastomer membrane free volume appreciated; According to the prior art, depending on the application, a variety of types of elastomeric diaphragm valves for the ventilation of camps in use.

The French patent application FR 850 245 / international registration WO 2009/090 120 / German publication DE 11 2009 000 106 presents a seal and a rolling bearing having such a seal. The seal is provided for mounting between two relatively rotating elements - in particular the outer and the inner ring of a roller bearing - wherein the seal has sealing areas, which are suitable, a static seal with z. B. the outer ring and a dynamic seal with z. B. the inner ring, wherein the dynamic sealing portion has a first and a second sealing lip, wherein the first sealing lip has a fluid-reactive coating, and which define an annular chamber formed in such a way that can be filled with lubricant, and the seal is formed such that they during contact with a fluid having at least the dynamic sealing area, allows movement of the lips at least in the radial direction towards the associated ring to make contact with that ring.

The sealing areas are connected by an insert or a frame in the form of a relatively stiff annular disc on which a sealing element consisting of nitrile rubber (NBR) or another elastomer is over-injected or vulcanized. On each of the opposite flanks of the rolling bearing is radially symmetrical such an annular seal to seal the radial space which exists between the outer and the inner ring; ventilation is not provided.

With the Italian patent IT TO 970 648 / European patent specification EP 892,471 /German translation DE 698 08 191 is a rolling bearing unit - presented in particular for the hub of a vehicle wheel, which is provided with at least one sealing device which closes the annular gap between the radially outer raceway and the radially inner race of the bearing and allows the electrostatic discharge through the bearing such that an annular Insert is coated with an electrostatically conductive V-shaped sealing lip so that the lip forms against a second annular insert chambers, one chamber is filled with electrically conductive grease and the other with grease and the tightness through a guided in the V-shaped lip Federring is reinforced.

Due to the mirror-symmetrical structure of the tandem ball bearing with conductive sealing means on both sides, there is no gas exchange with the internal cavities of the bearing.

A variety of patent applications - as exemplified by the Japanese application JP 5 784 097 / European registration EP 864 770 /German translation DE 698 00 162 - are concerned with the design of seals for rolling bearings - in particular the design of the sealing lips on the number, shape and material, such as the approximately 65 predominantly Japanese applications under "Rolling Bearing with Seal" - such. B. the applications JP 2010 106 953 . JP 2009 220 103 or JP 2006 320 984 , or the approximately 14 predominantly Japanese applications under "Seal Device for Rolling Bearing" - such. B. the applications JP 2009 185 858 . JP 2008 157 371 or JP 2008 121 820 , mainly concerning sealing devices for wheel bearings of the automotive industry.

In the European application EP 753 679 a rolling bearing is presented, where the inner sealing lip of the sealing device slides on the outer peripheral surface of the cylindrical portion of the mating ring and is deformed radially outwardly.

The European application EP 495,323 discloses a rolling bearing having a sealing means, wherein the outer and the middle sealing lip of the sealing member slide on a counter-member, while the inner sealing lip forms a small clearance with the outer peripheral surface of the cylindrical portion of the counter-ring; a similar structure is used in the American application U.S. 4,819,949 disclosed.

The Japanese Patent Publication JP 252 140 comprises a sealing device including a radially outer and a radially inner sealing ring - each formed with reinforcing elements, which is arranged between an outer ring and an inner ring of a bearing. The radially outer sealing ring is fixedly connected to the outer ring and carries a sealing element with one or two sealing lips whose tip ends is in sliding connection with the surface of the reinforcing element of the radially inner sealing ring. Conversely, the radially inner sealing ring is fixedly connected to the inner ring and carries a sealing element with one or two sealing lips whose tip ends is in sliding connection with the surface of the reinforcing element of the radially outer sealing ring.

In another sealing arrangement for bearings shows the publication JP 2 146 221 an inner ring with an angled reinforcing metal and an outer ring with a likewise angled second reinforcing metal and with the first forming a rectangular annular gap, wherein the second reinforcing ring comprises a hand-shaped sealing element, the tip ends of the three finger-like sealing lips on the inner surface of the first reinforcing ring sealingly slide.

Another revelation JP 3 121 224 has an inner ring and outer ring arrangement with L-shaped reinforcing rings as before, however, the attached to the reinforcing ring of the outer ring sealing element imprinted three differently mounted finger-like sealing lips.

A number of improvements of various kinds to the last-mentioned applications JP 252 140 . JP 2 146 221 and JP 3 121 224 then lead to the above Japanese application JP 5 784 097 / European registration EP 864 770 /German translation DE 698 00 162 , In the former publication, difficulties in manufacturing arise in view of increasing the cost of the entire sealing device. In the second publication, an improvement arises as the inner sealing lip becomes "duller" as it now "folds" during assembly. In the third publication of the forming lubricating film is too low and can be feared high friction losses between the sealing lips of the sealing element and the reinforcing metal of the inner ring. The incorporation of these improvements leads to a redesigned finger-like sealing element; All previous publications have in common that they close as close as possible and do not consider any exchange of gaseous media.

According to the Japanese patent application JP 752 496 / European registration EP 785 368 /German translation DE 697 17 687 a sealing device for a rolling bearing is presented, which consists of an inner and an outer sealing ring, depending formed from a over-molded with an elastic element reinforcing metal with each V-shaped sealing lips at the non-attached end. While the inner sealing ring is fixedly connected to the stationary inner ring and seals against the outer ring and the outer sealing ring, the outer sealing ring is arranged parallel to the inner, but sealingly secured against the stationary inner ring on the rotating outer ring.

The arrangement is specifically intended for wheel bearings of vehicles and should be splash-proof.

The American patent US 366,355 / German disclosure DE 195 47 741 presents a seal for a rolling bearing whose inner and / or outer ring each have an axial sealing groove at its axial end. The metal-reinforced sealing member comprises a ring of an elastomeric material having a plurality of circumferentially periodically arranged radially extending projections integrally formed on an outer or inner periphery of the sealing member. The projections are designed to provide a tight or press fit in the radial direction for sealing with respect to a bottom wall and an outer side wall of the sealing groove. Preferably, the radial interference fit of the sealing element biases this axially against an inner side wall of the sealing groove. The C-shaped, inwardly directed sealing element has an elastomeric part and a metallic reinforcing part in the one-piece dense composite, wherein the elastomeric part at its inner Diameter has a sealing lip or other conventional design, such. B. a labyrinth seal.

Further recent applications then have an additional function of the sealing device of the wheel bearing to the effect that in the context of Dichtungsvergusses the sensor and actuator of a decoder takes into account that a ring of alternately arranged permanent magnets are in conjunction with the rotating part of the camp and a static attached sensors motion sequences of the wheel bearing sensory detected and used as electrical signals for processing -. As the engine management - forwarded. This concerns z. B. the applications JP 2009 185 965 . JP 2007 192 383 . JP 2002 372 499 . FR 9 609 324 or FR 8 900 649 ,

The invention is therefore based on the object, a device according to the preamble of claim 1, a sealed bearing assembly with a semi-permeable elastomeric membrane - in particular to create a sealed rolling bearing with a closed by a semipermeable elastomer membrane free volume.

This object is achieved by the characterizing features of claim 1; to advantageous embodiments, the dependent claims. The aim is to build a sealed bearing assembly with a semi-permeable elastomeric membrane - in particular a sealed rolling bearing with a closed by a semi-permeable elastomer membrane free volume.

In bearing arrangements with rolling elements or rolling elements, these elements are disposed friction-reducing in an annular space between the outer and inner bearing rings. In general, sealing means are provided at the axial ends of such bearing assemblies to hold lubricant within the bearing assembly and to keep debris from entering the assembly where it may cause damage to rolling elements and rolling elements or raceway rings. Usually, such sealing devices are held on a bearing ring and rotate with this bearing ring - also called static sealing area - and can be brought into engagement with the other bearing ring to effect a seal - also called dynamic sealing area.

In some prior art sealing arrangements, a substantially rigid elastomeric sealing element, often made as a two or more layers of elastomer or metallic or hard plastic reinforcement, is incorporated into an annular sealing groove in a bearing ring. The sealing groove may be a V-shaped or other geometric shape having groove at one axial end of the bearing ring. By radially inwardly compressing a continuous circumference of the sealing device, the sealing element is installed over a retaining surface in the sealing groove. Due to its elasticity, the sealing element expands in the sealing groove radially outward and causes a seal with the bearing ring. To avoid tension and / or leakage of the sealing device with the bearing ring, attention must be paid to dimensional accuracy between the circumference of the sealing element and the dimensions of bearing ring and groove. At this point, it is also proposed to make short incisions or indentations on the circumferential line of the sealing device in order to ensure the stress-free introduction of the sealing element.

According to one aspect of the invention, sealing elements for a bearing arrangement with rolling elements or rolling elements are recommended, the outer and inner bearing rings and a plurality of rolling elements or rolling elements within an annular space therebetween, wherein between the at both ends, axially spaced sealing elements a free Volume remains, which tends to condensation, which is known to be promoted by rapid temperature changes at a given humidity and given pressure.

Therefore, according to an advantageous embodiment of the inventive novelty proposed to open the bearing assembly - based on the currently sealed free volume - semi-permeable means of a membrane such that - starting from a two-layer coated with elastomer metallic or hard plastic reinforcing member, substantially annular sealing element - This is provided at the dense annular surfaces with openings, which are coated in a further operation with a semi-permeable elastomeric membrane by two-component injection, so that the liquid lying behind the membrane free volume, but is open for a gas passage - d. H. the membrane is an absolute barrier for liquid media such as sprayed water and allows substances in the gaseous state - such as condensed water as humid air - to pass through it - so as well as any formed liquids enclosed in the free volume of the bearing to escape in the gaseous state ,

The subject matter of the invention will be further clarified below with reference to the accompanying drawings of exemplary embodiments. Show it

1 Bearing assembly, assembled, cut

2 Sealing device, detail, cut

3 Bearing arrangement with sealing device, removed

4 Sealing device, top view.

The same and equivalent components of the embodiments are each provided with the same reference numerals in the figures.

The description of the device according to the invention will be continued with reference to the explanation of the figures.

How out 1 can be seen in storage arrangements 1 . 2 . 3 with rolling elements or rolling elements 33 these elements in an annular space 50 between outer 32 and inner bearing rings 31 that have a common axis 49 have friction-reducing in raceways 43 . 44 guided and through a cage 34 arranged in the circumferential direction. In general, sealing devices 6 at the axial ends 41 . 42 provided such bearing assemblies; Usually, such sealing devices are on a bearing ring 31 . 32 in a sealing groove 52 held and rotate with this bearing ring - also static sealing area 62 called - and are with the other bearing ring 31 . 32 by means of a recess 57 . 58 engageable to effect a seal - also dynamic sealing area 63 called. Rolling elements or rolling elements can be balls - as shown - or they can be conical, spherical or cylindrical rollers of various kinds.

The annular sealing groove 52 to 2 is within the radially inner surface of the outer race 32 at an axial end 42 provided and consists essentially of a radial inner side wall 54 , a curved bottom wall 55 , a sloped outer sidewall 56 and an axial support surface 53 , The surfaces form with the sealing ring 61 the static sealing area 62 , In cross-section, these defined surfaces form a continuous outline; the substantially radial inner sidewall may have an angle to form a draft. The inner bearing ring 31 has at its radially outer surface an inclined recess 57 on, in a convex conical recess 58 passes. The inclined recess extends from its axial end 41 axially inward and radially outward - similar to a ramp - and forms with the sealing lips 71 of the sealing ring 61 of the sealing element 6 the dynamic sealing area 63 , When using other types of seals, such as. As a labyrinth seal, other geometrical configurations of the dynamic sealing area can be selected. Also, the assignment of the static sealing area 62 to the inner bearing ring 31 and the dynamic sealing area 63 to the outer bearing ring 32 possible, as is the possible sealing device 6 with several, oppositely arranged sealing rings 61 calls.

According to the prior art, in some sealing arrangements 6 a substantially rigid elastomeric - often as two-layer coated with elastomer metallic or made of a hard plastic reinforcing member - sealing ring 61 in an annular sealing groove 52 in a bearing ring 31 . 32 built-in. The sealing groove of the static sealing area 62 may be an approximately V-shaped or other geometric shape having groove at one axial end of the bearing ring. By radial, inwardly compressing a continuous periphery of the sealing device of the sealing ring 61 over a holding surface 53 mounted in the sealing groove. At this point it is also proposed on the perimeter of the sealing device 61 make short cuts or notches to ensure the stress-free insertion and location of the sealing element.

According to a further aspect of the invention are sealing elements 6 for a bearing assembly 1 with rolling elements or rolling elements 33 recommended, the outer 32 and inner bearing rings 31 and a plurality of rolling elements or rolling elements within an annular space 50 between, with between the at both ends 41 . 42 , in axial distance 48 from each other attached sealing elements a free volume 51 remains, which among other things tends to condensation.

3 shows the bearing assembly 1 . 2 . 3 with removed sealing devices 6 , The sealing ring 61 has an elastomeric part 1 64 and a reinforcing metallic or hard plastic part 65 on whose cross-section approximately C-shaped or convex from the rolling body 33 can go away. The elastomer part 1 extends in the region of the static sealing area 62 z. B. the outer periphery of the reinforcing member axially and radially outwardly as a substantially radial surface 66 and ramp surface 67 , then axially outward as a cylindrical section 68 and notched section 69 and overall as a static sealing area 62 the geometric shape of the annular sealing groove 52 following, before moving into a flat, reinforcing surface 65 parallel radial surface 70 passes so that the sealing groove 52 for the elastomeric part 1 in this static area - not least by the holding surface 53 - occupies a fixed or press fit in the radial direction. The notched section 69 the elastomeric part 1 contacted with the holding surface 53 of the outer bearing ring 32 , The elastomer part 1 covers not from the inside, the rolling surface directed to the reinforcing surface 65 off, the clearance for rolling elements 33 and cage 34 forms. The Elstomer part 1 64 can be at its inner diameter in the dynamic sealing area 63 x-shaped sealing lips 71 which may also have another conventional design - such as a labyrinth seal - and those with the inclined recess 57 of the inner bearing ring 31 contact tightly. The sealing ring 61 has a radial distance of the free volume 51 of the annular space 50 breakthroughs 72 in the reinforcement section 65 on, with a semipermeable elastomeric membrane. 2 73 coated or sealed, forming the liquid-tight gas channel for the free volume. The geometric surface design of the breakthrough 72 is the geometry of the sealing ring 61 customized; the size of the aperture is parameterized by the semipermeable membrane material, its thickness, by climatic data and the permeate. Elastomer part 1 64 and elastomeric membrane 2 73 can be plastic-sprayed in the 2K process.

4 shows the sealing device 6 from 2 and 3 as seen in the axial direction. The sealing ring 61 is characterized by a static sealing area 62 , which is in place of the fixed clamping of the sealing ring by fixed or press fit 66 , ..., 70 in the radial direction in an annular sealing groove 52 at the front ends 41 . 42 of the bottom bracket 31 or outer bearing ring 32 results; this may affect the inner or outer diameter of the sealing ring. An appropriate design of the dynamic sealing area 63 with internal sealing lip 71 experiences the sealing ring as a counterpart to the static sealing area 62 , The structure of the sealing ring consists of an elastomer part. 1 64 , which by a dense annular metal or hard plastic part 65 is reinforced. Furthermore, the sealing ring of the inventive novelty is characterized by breakthroughs 72 in radial height to the free volume 51 of the annular space 50 out. These breakthroughs, which are not subject to any geometric form of constraint, form a semipermeable elastomer membrane 2 73 provided, the liquid-tight gas channel for the free volume of the annular space. The membrane can in the 2K process with the elastomer part 1 64 and the reinforcement part 65 be integrally injection molded plastic or be tightly joined as prefabricated injection-molded insert with the reinforcing and the elastomer part 1. The permeability of the thus formed gas channel for the permeate is dependent on the membrane material used and its thickness, on the climatic environmental conditions and the passage area of the openings. Since the membrane gas permeability behaves inversely proportional to the material thickness, has the elastomeric membrane 2 Film thickness on. In order to process this membrane, applying either by injection molding or as a tinfoil, the hole spacing of the openings must be reduced or the openings provided with a grid as a carrier or a prefabricated injection-molded insert to be prepared as a film carrier. According to the figure, the breakthrough 72 with a number of different grid and support structures 74 which are used as a support depending on the selected membrane and the selected method.

According to a further embodiment of the invention is as Einlege- and / or molded part and a sandwichartigiger structure of a coarsely permeable and a fine-permeable membrane material conceivable.

A further embodiment of the invention provides to doctor the elastomeric membrane material by means of a carrier screen and to install or overmold metal or plastic sieve with membrane material as an insert.

A further embodiment of the invention provides that the membrane carrier is a particularly flat-mounted mounted part for receiving the elastomer.

Another application of the inventive novelty is given by a multiple arrangement of sealing rings, wherein the sealing regions are arranged rectified, opposite or labyrinthine.

Another form of expression of the inventive novelty is given by the fact that on one side statically mounted sealing rings by a z. B. externally clamped ring spring mechanical pressure is exerted on the dynamic sealing area.

In a further advantageous embodiment, the elastomeric membrane is installed semipermeable acting in a multiple arrangement of sealing rings.

According to a further embodiment, the labyrinthine gas channel-forming semipermeable, strapless or membrane-shaped apertures in a multiple sealing ring arrangement are offset from each other by a rotation angle.

Storage arrangements subject to particularly temperature-dependent cleaning processes are affected by the formation of condensation in the free volume and benefit in particular from the solutions presented above. When selecting the membrane material, the application and environment must be taken into account.

Advantageous developments of the invention are the subject of the dependent claims; the numerous possibilities and advantages of the design The invention is reflected in the number of property rights claims.

LIST OF REFERENCE NUMBERS

1

bearing arrangement

2

roller bearing

3

radial bearings

31

Inner bearing ring

32

Outer bearing ring

33

Rolling element, rolling element, ball, roller

34

Cage, storekeeper

35

Bore diameter inner ring

36

Sheath diameter outer ring

37

Shoulder diameter inner ring

38

Shoulder diameter outer ring

39

Ring groove (not shown)

40

Snap ring (not shown)

41

Front side inner ring

42

Front side outer ring

43

Raceway inner ring

44

Raceway outer ring

45

Edge distance inner ring

46

Edge distance outer ring

47

Bearing diameter, middle

48

Total width of bearings

49

Axis, central

50

Space, ring-shaped

51

Volume, free

52

Retaining groove seal, sealing groove, annular, ring groove

53

holding surface

54

Sidewall, inside

55

bottom wall

56

Sidewall, outside

57

Recess, inclined

58

Recess, conical

6

Sealing device, sealing element

61

seal

62

Sealing area, static

63

Sealing area, dynamic

64

Elastomer part 1

65

reinforcing part

66

Surface, radial

67

ramp surface

68

Section, cylindrical

69

Section, notched

70

Surface, radial, parallel

71

sealing lip

72

breakthrough

73

Elastomeric membrane 2, semipermeable

74

Braid, grid, sieve, prop, carrier

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• FR 850245 [0028]
• WO 2009/090120 [0028]
• DE 112009000106 [0028]
• IT 970648 TO [0030]
• EP 892471 [0030]
• DE 69808191 [0030]
• JP 5784097 [0032, 0038]
• EP 864770 [0032, 0038]
• DE 69800162 [0032, 0038]
• JP 2010106953 [0032]
• JP 2009220103 [0032]
• JP 2006320984 [0032]
• JP 2009185858 [0032]
• JP 2008157371 [0032]
• JP 2008121820 [0032]
• EP 753679 [0033]
• EP 495323 [0034]
• US 4819949 [0034]
• JP 252140 [0035, 0038]
• JP 2146221 [0036, 0038]
• JP 3121224 [0037, 0038]
• JP 752496 [0039]
• EP 785368 [0039]
• DE 69717687 [0039]
• US 366355 [0041]
• DE 19547741 A [0041]
• JP 2009185965 [0042]
• JP 2007192383 [0042]
• JP 2002372499 [0042]
• FR 9609324 [0042]
• FR 8900649 [0042]

Cited non-patent literature

• DIN 53 380 [0019]
• DIN 53 122 [0019]

Claims (10)

Sealed bearing arrangement ( 1 ) with a semipermeable elastomer membrane - in particular a sealed rolling bearing ( 2 ) with a free volume closed by a semipermeable elastomer membrane - which external ( 32 ) and inner bearing rings ( 31 ) and in between a variety of in careers ( 43 . 44 ) moving, by stockholders ( 34 ) guided rolling bodies ( 33 ) within an annular space ( 50 ), one of the bearing rings ( 31 . 32 ) an annular sealing groove ( 52 ) at an axial end ( 41 . 42 ), wherein the sealing groove has an inner side wall ( 54 ), a bottom wall ( 55 ), an outer side wall ( 56 ) as well as a holding surface ( 53 ) and with a sealing element ( 6 ) the static sealing area ( 62 ), and the other bearing ring ( 32 . 31 ) an annular, conical and inclined recess ( 57 . 58 ) and with the means of sealing lips ( 71 ) sealing element ( 6 ) the dynamic sealing area ( 63 ), characterized in that - the sealing device ( 6 ) made of circular sealing rings ( 61 ) on both sides of the axial ends of the bearing rings ( 31 . 32 ) - the sealing ring ( 61 ) of an elastomeric material 1 ( 64 ) and has an outer and an inner circumference - the sealing ring ( 61 ) in the axial direction of a sandwich-type construction with a reinforcing part ( 65 ) - between the bearing rings ( 31 . 32 ) and the fitted sealing rings ( 61 ) located annular space ( 50 ) a free volume ( 51 ) - the sealing rings ( 61 ) in the radial height of the free volume ( 51 ) Breakthroughs ( 72 ) - the breakthroughs ( 72 ) each by a breathing elastomeric membrane 2 ( 73 ) are closed semipermeable and form a gas channel. Bearing arrangement ( 1 ) with an elastomeric membrane according to claim 1, characterized in that the elastomeric membrane 2 ( 73 ) in the area of the sealing ring breakthroughs ( 72 ) by a mesh, grid or carrier ( 74 ) is supported. Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 and 2, characterized in that the elastomeric membrane 2 ( 73 ) is applied in 2K or xK (component) plastic spraying (x> 2) or densely joined as ready-sprayed or as a carrier / membrane film insert. Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 to 3, characterized in that the carrier ( 74 ) for the elastomeric membrane 2 ( 73 ) is made of metal or plastic. Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 to 4, characterized in that the sealing ring breakthroughs ( 72 ) are drilled, stamped, milled and / or lasered and / or are part of a plastic injection molding tool. Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 to 5, characterized in that the elastomeric membrane 2 ( 73 ) and the carrier ( 74 ) a sandwich-like structure of differently porous membrane materials is at least one semipermeable layer containing. Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 to 6, characterized in that the sealing device ( 6 ) by an extended in the axial direction multiple arrangement of sealing rings ( 61 ), with equilateral, opposite or labyrinth-like static ( 62 ) and dynamic sealing areas ( 63 ). Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 to 7, characterized in that the elastomeric membrane 2 ( 73 ) in a multiple arrangement of sealing rings ( 61 ) semipermeable a gas channel is installed. Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 to 8, characterized in that on the one side, in the static sealing area ( 62 ) mounted sealing rings ( 61 ) by a clamped annular spring mechanical pressure on the dynamic sealing area ( 63 ) is exercised. Bearing arrangement ( 1 ) with an elastomeric membrane according to at least one of claims 1 to 9, characterized in that the gas channel forming semipermeable strapless or -behafteten membrane breakthroughs ( 72 . 73 . 74 ) in a multiple sealing ring arrangement ( 61 ) are not in a flight, but are offset by a rotation angle to each other.

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