US2694606A - Lubricant pad for bearings - Google Patents

Description

NOV. 16, 1954 R. ETzKoRN LUBRICANT PAD FOR BEARINGS Filed Oct. 18 1949 JNI/ENTOR.

g"WLF ETz KoR/v BY United States Patent LUBRICANT PAD Fon BEARINGS Rudolf Etzkom, Murg, Baden, Germany, assignor, by mesne assignments, to Cefas Aktiengesellschaft, Zurich, Switzerland, a corporation of Switzerland Application October 18, 1949, Serial No. 122,137

Claims priority, application Switzerland October 22, 1948 7 Claims. (Cl. 308-243) My present invention relates to improvements in capillary action textile lubricant pads for bearings, in particular for railway car journals; and the main object of my improvements is to continuously and uniformly also incorporate into the contact surface such lubricants which cannot be supplied through capillary action, without, however, impairing the capillary-action oil supply.

The bearings of railway car journals often comprise an upper brass against which the journals are pressed through the weight of the vehicle and a lubricant pad which contacts the journal from below. The said pad comprises a textile strand structure and a wire support therefor, and is spring-pressed against the journal. On the side adjacent the journal, the threads are woven loop-like into the pad, while at the bottom side the threads are immersed in form of wicks in the oil chamber. The said wicks suck oil up into the fabric loops or thread nooses which, by virtue of the spring pressure, contact and oil the axle journal. A requirement for such action is, however, that the axle-journal surfaces are of high and uniform smoothness, Without hair cracks and the like.

In power-vehicle motors and gears, the use of graphited oils has proved of Value. Graphite, as is well known in the art, is capable of smoothing out minor rough spots in bearing surfaces and increasing the lubricating capacity of the oil. Through the use of oils containing graphite in colloidal dispersion, the operating properties of the bearings and, thus, the safety of operation are substantially improved. The use of such oils, however, is impossible in those cases in which wicks are used, since the latter although capable of adsorbing the oil, are not capable of feeding the colloidal graphite to the point of lubrication. It has not been possible, therefore, up to now to exploit the advantages afforded through the use of graphite oil.

It has been attempted to coat the threads of lubricant pads with graphite, as is done, e. g., in the case of stufiingbox packings, but the results were disappointing, since the graphite tends to plug the capillaries. It thus has not been possible, up to the present, to satisfactorily feed graphite to axle-journals of the type indicated.

According to my present invention, the threads contacting the axle-journal surface consist, partly at least, of artificial fibres in which lubricant particles are stored or embodied. In one example, all the threads contacting the journal consist of single fibres in which are embodied minute particles of a lubricant, preferably distributed uniformly over the entire fibre cross-section. In another example, the said fibres are present in the loop in cornpany with other natural or artificial fibres. In any case, it is of essence that lubricant particles are embodied in at least part of the threads in the sections in which they contact the axle-journal. With a view of simplifying the manufacture of the pad, the wicks which are immersed in the oil, may be made of the same fibres as the thread loops.

By embodying in the fibrous mass solid lubricants or, again, liquid lubricants which cannot be fed through capillary action to the axle journals, these lubricants still can be supplied to the contact face. It thus is possible to utilize the favorable action of solid materials such as graphite, talcum, or of highly viscous oils and fats.

Artificial fibres made from solutions having a basis of cellulose, such as may be made e. g. according to the viscose process or the cuprammonium silk process, are best suited for the purpose of my present invention, the

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finely` dispersed lubricant being incorporated in the spinning solution and anchored byvirtue of the spinning process in the fibres uniformly distributed across the entire fibre cross-section.

In order to understand clearly this invention an example is illustrated in the accompanying drawing, in which Fig. 1 shows a sectional view of a lubricant structed according to this invention, and

Fig. 2 illustrates a cross section through a number of particular fibers.

Fig. l shows a tissuev or cloth 1 into which threads 2 are woven or sewed. The threads form loops on the upper part of the tissue 1. Below thecloth 1 are provided threads 3 which act as wicks.

The pad is fastened to a frame (not shown). In the interest of better clarity only a few of the threads 3 are shown in the drawing.

According to this invention the fibers of the threads 2 are made artificially and particles of lubricants are incorporated into ythe particular fibers.

Fig. 2 illustrates a cross-section 'through a number of particular fibers 4 of the threads 2. It is'shown, how the particles 5 of lubricant are incorporated into the fibers.

It is not necessary that lubricant particles be incorporated also into the fibers of the threads 3, although in order to have a simpler fabrication of the pad, threads 2 and 3 may consist of the same material.

The threads 3 hanging from the tissue 1 reach into an oil container and oil is supplied by capillary action to the threads 2, which are in contact with the part to be lubricated, for instance a journal of an axle. If by friction between the threads 2 and the moving part to be lubricated the fibers of the thread gradually wear out, the lubricant incorporated therein is set free and takes part in the lubrication process.

The quantity of incorporated lubricant may vary in wide limits. The upper limit is defined by the requisite rubbing strength and stability of the fibre, which depends on one hand on the nature of the bearing stress and, on the other hand, on the combined use of fibres having no incorporations. In general, lubricant contents from l0 to 80 percent by weight of the entire fiber mass have proved useful, figured for the impregnated fiber and not considering eventual other fibers used in combination therewith.

According to one example of my present invention, there may be provided, aside from the artificial fibres impregnated with graphite, talcum or the like, also artificial fibres impregnated with another lubricant, finely dispersed therein, such as fats or oils. The latter preferably shall have a higher boiling point and flash point than, for instance, the oils which are fed by capillary action through the wicks to the contact surfaces.

A preferred example of such latter combination comprises, in addition to the solid lubricant, fat or oil embodied in the same fiber.

In use, as already stated above the pads according to my present invention continuously provide lubricant for the contact surfaces, in addition to the oil fed through the wicks by capillary action, owing to a slight rubbing wear of the fibers. The result of such additional lubrication is a substantial improvement of the lubricating property of the sucked-up oil. It has to be further noted that the fibers used for the pad according to my present invention, in contradistinction with pads of prior art, shall have a stability as high as possible, i. e. the fibres shall oppose as much as possible a smoothing and felting on the contact surface due to friction under the pressure of the contact spring. It has been found that the fiber which contains solids substantially maintains its initial shaped despite the pressing and friction, and thus is more suitable for feeding oil to the contact faces than the fibers used up to the present time. The stability of the fibers according to my present invention can be -attributed to the large quantity of embodied solids on one hand, and may be further enhanced by an appropriate process of manufacture.

The oil output of the wick, i. e. the feed of oil to the axle journal, is not impaired by the incorporations in the ber. On the contrary, in comparison with the pad connatural fibres used in prior art, such output can be substantiall-yincreasedby using fibers ofsmall single standard or fineness, whereby the number of capillaries is increased.

When, owing tolack^' ofi oil', soiling and.l the like-, ther temperature of the` bearing` is. raised:` above its. normalf temperature of operation, the. fiber4 mass. is; destroyed, and relatively large quantities of the embodied: lubricantsA are set free. The operating properties thereby. are improved. insuch degree, also. at these higher bearing tem-A peratures, as to prevent in most cases further overheating and seizing of the bearings. Testsy of lubricating pads according to mypresentY invention, have shown that they areV substantially more. reliable in. operation than pads of prior art.

What'I claim as new and. desire to secure by Letters Patent', is:

1.- A lubricant textilematerial for bearings, comprising, in combination, elongated threads. each thread being formed of a plurality; of fibers andV having first portions adapted toy Contactv the surface to. belubricated and second portions adapted to be immersed in a bathof liquid lubricant so. that liquid lubricant may be carried to said first: portions by capillary action; at least some of. said fibers consisting of a composition ofsynthetic substance. andparticles of a lubricating substance embedded therein, so. thatI upon disintegration. of: the synthetic substance forming part of said fiber the lubricating substance embedded therein is freed for lubricating action.

2. A lubricant textile materiali for bearings, compris. 30

ing, in combination, a. plurality ofelongated yarns each composed of individual fibers; at least some of said fibers consisting of a composition of: a synthetic substance and particles of a. lubricatingl substance embedded therein, so that upon disintegration of the synthetic substance forming part of said fiber the lubricating substance embedded therein is freed for lubricating action,` said yarns having the fibers thereof arranged formingy interstices between themselves andi having afirst portionadapted to contact the surface to be lubricated anda second portion adapted to be immersed in a bath of liqudlubricant, sothat liquidlubricant may'be carried to said first portions of' said yarnsV by` capillary action .in the interstced space between the fibers.

3. A lubricant textile material forbearings, compris- 4. ing, in combination, elongated threads each thread being formed' of` a pluralityof fibersV and having first portions adapted to contact the surface to be lubricated and second portions adapted to be immersed in a bath of liquid lubricant so that liquid lubricant may be carried to said first portions by capillary action; at least some of said fibers consisting of a. composition of synthetic substance and partclesofa lubricating substance embedded therein, so.` that upon disintegration of the synthetic substance forming part Qff said fiber ther lubricating substance embedded thereink is freed for lubricating action, said particles of lubricating substance having a higher boiling oit. andflashl point than said liquid. lubricant in said 4. A lubricantv textile material as defined in claim 1, wherein said lubricating substance is graphite.

5. A lubricant textile material1 as defined in claim l, wherein said lubricating substance is talcum.

6,. A lubricant textile material as defined' in claim l, wherein said lubricating substance is a highly viscous oil.

7. A lubricant textile material' as defined in claim 1, wherein said synthetic substance is a synthetic cellulose base substance.

References Cited in the. file. Qi this Patent UNI-TED STATES, PATENTS Number. Name Date 3,215,966 Piercer Sept. 8, 1885 733,156.5 Cole` July 7, 1903 765,176 Gill July 19, 1904 787,752A Griin Apr. 18, 1905 997,501 Howe July 11, 1911 1542733401 Woodman Aug. 29, 1922 2,126,042. Reinz Aug. 9, 1938 2116.6J739 Karplus: July 18, 1939 2,291,483 Miller July 28, 1942 233,137,986; Fryl Dec. 28, 1943 FOREIGN PATENTS Number Countryk Date 1,234: GreatBritain A. D. 1867

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