US2753229A - Bearing construction - Google Patents

Description

July 3, 1956 w. c. QUEER, SR

BEARING CONSTRUCTION 3 Sheets-Sheet Filed March ll, 1953 INVENTOR. /L m COLGeZ' I,

9 1956 w. c. QUEER, SR 2,753,229

BEARING CONSTRUCTION Filed March ll, 1953 3 Sheets-Sheet 2 8 u! {I FT' r 36 32 34. 4 ;T E l 1 Q+ r I IN V EN TOR.

July 3, 1956 w. c. QUEER SR &753329 EEEAMNG CQNTRUCMGN t illiain C. Queer, r., lndiana Harhor, find., assignor to finland Steel (Company, Chicago, llll., a eorporation oti Delaware Application March Jill, 1953, Serial Ne., Mifw'' filaims., (Ci. Sitit-1121) This invention relates to a novel hearing .means and more particularly to an improved hearing Construction for journalling rolls and the like.

in the continuous treatment of metal sheet or strip naterial, the metal is subjected to a sequence of treating operations carried out in separate zones. For example, some ot the more usual treatng Operations are hot rolliug, cold rolling, cleaning, annealing or other types of heat treatment, gas treatment, galvanizing, etc. As the metal sheet or strip is passed through the successivo zones of treatment, the direction of movement of the sheet is controlled by means of rolls of difierent types over which the metal sheet is trained. These rolls are variously referred to as sinker rolls, idlers, sheaves, etc. dependent upon the function of the particular roll. Frequently, a treating step will involve passing the metal sheet or strip through a tank or vessel containing a liquid bath, for eX- ample, an aqucous caustic solution in the case of the cleaning of the metal to remove oil or grease therefrom, or a moltcn zine bath in the case of a galvanizing step. in such instances, the so-called sinker roll is usually wholly or partially submerged in the liquid bath and the metal sheet is caused to pass downwardly under the sinker roll and thcnce upwardly to the next stage ot' the process.

l have found that when a roll is required to be operated either partially or wholly submerged in a liquid bath such as nolten metal or aqueous caustic solution, serious difculties are often experienced with the operation of the roll bearings. lfhus, in the case of a caustic cleaning solution or the like, there is a continuous ac cumulation of oil debris and scun resulting from the cleaning of the metal sheet and this material frequently results in sticking, fouling, and generally unsatisfactory operation of the roll bearings. In the case of a high temperature molten metal bath, a similar sthuation is encountered due to the accunulation of dross and these dificulties are further aggravated by the fact that the bath operates at a relatively high temperature.

Accordingly, a primary object of my invention is to provide a novel and improved hearing means for journalling rolls ot the character described above.

A further object of the invention is to provide an in1- proved hearing means which is particularly adapted for use with roll Operating in a liqud bath.

Another object of the invention is to provide an improved hearing Construction for sinker rolls, idlers, sheaves, and the like which are used in apparatus for the continuous treatment of metal sheet and strip.

A more specific object of the invention is to provide an improved bearing means for rolls intended for opera tion in a caustic solution or in a molten metal bath.

Otier objects and advantages of the invention will become npparent from the subsequent detailed description taken in conjunction with the accompanying drawings, wherein:

Fig. l is a semidiagrammatic View showing a portion of a treating apparatus for the continuous cleaning of metal sheet with a caustic solution;

Fig. is an elevational View of a portion of the apparatus seen in Fig. 1;

Fig. 3 a transverse cross-sectional View on an enlarged scale substantially as seen along the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary View as seen along the line of Fig 3;

Pig. 5 is an axial cross-sectional View taken along the the line 5--5 of Fig. 3;

Fig. 6 is a view similar to Fig. 5 but showing a different einbodiinent of the invention; and

Fig. 7 is a transverse cross-sectional View as taken along the line '7-7 of Fig. 6.

Referring first to Pigs. 1 and 2, the treating vessel or al'lk is designated fragmentarily at liti and is adapted to contain an aqueous caustic solution, such solution being commonly used, for example, to remove the oily lubricant applicd to a metal sheet in a preceding cold reduction step. The metal sheet, indicated at llll, passes downwardly through the caustic solution in the tank 10, underneath a lower roll 12, upwardly over an upper roll 113, downwardly again and under another lower roll M, and thence upwardly and out of the tank 10.

Each of the rolls 12, 13 and M comprises a metal cylinder na having a pair of circular end members 117 Secured thereto for rigidly supporting the roll on an elongated axial shaft 1%, the roll being rotatable with the shaft ?iii as a unit. To avoid any buoyant effect of the liquid on the submerged rolls, the cylinder 16 contains a multiplicity of apertures or pertorations 19 which may be arranged in axially extending rows or in any other suitable pattern. in addition, the end members 17 are provided with a plurality of apertures 21. Thus, the caustic solution in tank i@ may flow frcely into the interior of the rolls to avoid trapping of air therein.

Preferably, the outer periphery of the roll cylinder lfi is formed with a pluralty of helical grooves extending from end to end of the cylinder. For purposes of illustration, i have indicated two such grooves in Fig. 2 by the helically extending lines 22 and 23, these two grooves starting at the center of the roll on opposite sides thereof and extending to the left-hand end of the: roll. A corresponding pair of helical grooves extend from the same starting points to the right-hand end of the roll. Other similar helical grooves starting at the central portion of the roll and extending outwardly in both directions to the opposite ends of the roll are indicated fragmentarily at 24-. The purpose of these grooves is to prevent the accumulation of saponified oil or grease, scurn, or other foreign matter which would otherwise tend to collect between the roil surface and the metal sheet lil. The provision of the helically extending peripheral grooves aifords a plurality of passages or Channels within which this debris may collect and be washed away from the roll by the action of the liquid bath. i

Coming now to the novel feature of my invention, the .lower roll 12 in Fig. 2 is shown with a pair of bearings, designated generally at Zt?, mounted on the projecting end portions of the shaft liti for rotatably supporting the letter. lt will be understood that these bearings 26 are held against rotation in a suitable supporting structure such as a standard, arm, pillow block, or the like, but this supporting structure has been omitted froni Figs. 1 and 2 in the interests of Simplicity. The structural details of the novel hearing unit 26 are fully illustrated in Pigs, 3 to 5 wherein it will be seen that the hearing comprises an annular hearing member or sleeve 27 which is received within a two-part housing or support indicated fragmentarily at 238. A pair of pins or keys 29 extend from the stationary supporting structure 28 into corresponding enlarged apertures 31 in the hearing member 27 for holding the latter against rotation. As best seen in Fig. 5, the coacting portions of the hearing member 27 and the supporting structure 23 have a generally spherical curvature so that the bearings at the opposite ends of the shaft 18 are automatically aligned in a manner well understood in the bearing art. The clearance between the pins 29 and the enlargedopenings 31, of course, permits the necessary relative movement between the bearing member 27 and the supporting structure 28 to eect the desired self-alignment at both ends of the roll.

As Will be clear from Fig. 3, the interior of the bearing member or sleeve 27 is relatively free and open except for a plurality of radially extending projections or humps, three such projections being indicated at 32 at one side of the bearing member 27 and a fourth hump or projection 33 being disposed at the diametrically opposite side of the bearing member 27. Each of the projections or humps 32 and 33 carries a flat-surfaced bearing element, designated at 34 and 36, respectively, in the form of replaceable bars or strips of a special hard alloy such as Carboloy or the like. The shaft 18 has an end portion 37 of reduced diameter so as to provide a radially extending shoulder 38, and this reduced end portion 37 is fitted with a sleeve or bushing 39 having an outermost layer 41 of special bearing material such as Stelli-te or the like. As will be readily understood, the bearing surface 41 of the sleeve 39 eontacts the inner flat surfaces of the bearing elements 34 and 36 so that there is substantially only line contact between the coacting bearing portions at all times.

During operation of the apparatus, the metal sheet 11 which passes under the roll 12 is in tension and there is, therefore, a pronounced tendency to lift the sinker roll and its shaft upwardly. The dimensions of the bearing Construction 26 relative to the shaft end portion 37 and its sleeve are such that there is a slight clearance between the shaft sleeve and the bearing elements. As a result, the end shaft portiors 37 of the sinker roll are lifted upwardly into bearing engagement with the uppermost bearing elements 34 (as best seen in Fig. 3) and there is no contact with the -lowermost bearing element 36. Of course, it will be understood that the -resultant clearance, as indicated at 42 in Fig. 3, between the shaft sleeve and the lowermost bearing element 36 is exaggerated for purposes of illustration. When the tension of the metal strip 11 is relaxed, such as when the ap- I paratus is idle, the roll shaft Will drop down into contact with the lower bearing element 36 and there will be a correspondingly slight clearance or space between the shaft and the upper bearing elements 34. Thus, the lower bearing element 36 functions primarily as a shaft support when the roll is stationary, and during rotation of the roll the shaft is in contact only with the upper bearing elements 34.

'One of the important features of the invention resides in the fact that the bearing elements or bars 34 and 36 are frictionally fitted in corresponding slots provided in the radial hurnps of the bearing sleeve 27 and these bars may thusbe readily replaced whenever necessary. From Fig. 3, it will be understood that the bearing bars 34 are pressed outwardly and held in place in their slots by the upward pressure of .the roll shaft when the latter is being lifted upwardly. When the device is stationary and the sha-ft rests on :the lower bearing bar 36, the upper bars 34 may drop down to a slight extent into contact with the shaft depending upon the tightness of the fit of 'the bars in their supporting slots. However, this is not objectionable since the bars 34 are readily pressed back into seated engagement in their slots when the roll and its shaft are lifted upwardly. In order to permit use of the same bearing Construction for the upper roll '1-3 (Fg. 1) wherein the bearing 26 is reversed so that the single bearing element 36 is uppermost, it is necessary to provide some means for holding the bar 36in its slot. For this reason I provide a pair of pins 43 extending between the bars 36 and the sleeve member 27 for retaining the bar 36 in place. Thus, even when the bearing 'structure 26 is turned upside down as in the upper portion of Fig. 1, the bearing bar 36 is prevented from dropping down into engagement with the roll shaft. It will be apparent that when :the bearing 26 is used in conjunction with an upper roll such as the roll 13 in Fig. 1, the roll shaft will remain at all times in bearing engagement with the elements 34 and 'the element 36 plays no particular function.

As a result of the bearing construction described above, it will be seen that a substantially arcuate clearance or space is provided between the bearing sleeve 27 and the roll shaft. consequently, the caustic solution or other liquid medium in which the roll is immersed can flow freely through this arcuate space thereby avoiding restrictions or pockets tending to cause accumulation of foreign matter in the bearing areas. Furthermore, the bearing contact between the shaft sleeve 'and the bearing elements is substantially only a line contact at a plurality of circumferentially spaced points so 'that the tendency toward obstruction of the proper 'operation of the bearing by accumulated foreign matter is further minimized. Also, as seen in Fig. 4-, the contact surface of each of the bearing elements 34 and 36 is provided With 'a plurality of parallel diagonal grooves 44 which further facilitate unobstructed trouble-free operation of the bearing. The grooves 44 provide channels or spaces in which the foreign matter can gather and ultirnately be Washed away from the bearing area by the norma-1 movement of the caustic solution or other liquid in which the bearing operates. Thus, there are no completely sealed pockets or the like between the bearing elements and the roll shaft, and the normal action of the liquid surrounding the bearing is suficent to keep the bearing area free of accumulated foreign material.

Referring now to Fig. 5, it will be seen that the bearing elements or bars 34 and 36 abut against the end wall, indicated at 46, of each slot at the outer axial end of the bearing sleeve 27, and at the opposite end of the bearing the bars 34 and 36 project beyond the sleeve 27, as at 47. A thrust ring 48 is secured to the bearing sleeve 39 on the shaft end portion 37 by means of a plurality of radial retainer pins 49 eX-tending through the ring 48 into engagement with the outer surface 41 of the shaft sleeve. T'he thrust ring 48 is thus held against the shaft shoulder 38 on one side thereof and the projecting portions 47 of the bearing elements or bars 34 and 36 coact with the ring 48 for receiving the aXial thrust from the shaft 18. Thus, the projecting ends '47 of the radial bearing elements 34 and 36 function as stationary thrust bearing members in cooperation with the ring 48 which rotates with the rol-l shaft.

In Figs. 6 and 7 I have illustrated a modification of the bearing structure which is particularly useful in conjuncton with a sinker roll in a galvanizing unit. In other words, the roll operates while immersed in a molten bath of zine so that the bearing Construction for the roll must be such as to avoid operating difiiculties due to accumulations of dross and relatively high Operating temperatures.

The sinker roll is indicated at 51 and is provided With an aXially projecting shaft portion 52 having an outer end 53 of reduced diameter so as to provide a shoulder 54. A sleeve 56 having an outer layer 57 of bearing metal such as Stellite or Carboloy is fitted over the reduced end 53 of the roll shaft in abutment with .the shoulder '54. As in the previously described form of the invention, the bearing unit comprises 'a bearing member or sleeve 58 having a general ly spherical self-aligning seat within a two-part bearing housing 59 which is in turn mounted in the lower end of a supporting arm indicated fragmentarily at 61. In the same general manner as in thefirst described embodiment, the bearing member or sleeve 58 is relatively free and open (Fig. 7) except for a plurality of radially extending hurnps 62, three such hurnps or projections being shown. Each of the projections 62 carries a flat-surfaced bearing element or bar 63 for radial bearing engagement in line contant with the outer surface of the shaft sleeve. A slight clearance is indicated on an exaggerated sea-le at 64 between the lower bearing element 6.3 and the shafit, this clearance resulting from the upward lifting of the roll `51 and its shaft under the tension of the sheet passing thereunder. For the same reasons hereinbefore described in detail, it will be seen that the bearing Construction is kept free of accumulations of dross or other foreign matter in the molten metal bath and can, there'fore, operate with a minimum of Operating diicultiesr The embodiment of the invention shown in Figs. 6 and 7 differs from the first described embodiment primarily in the thrust hearing arrangement. In this instance the inner axial end of the hearing sleeve 58 has a radially extending fiange 66 adjacent the aXial end of the roll 51 and carrying a plurality of thrust hearing segments or inserts 67 of Carboloy or the like, three such segments 67 being shown here. These thrust bearing segments 67 cooperate with a hard hearing surface 68, such as Stellite, provided on the outer face of a thrust Washer 69 at the end of the roll Sl. Thus, the segments 67 constitute the stationary or non-rotating portions of the thrust hearing which coact with the rotating thrust bearing surface 68.

Although the invention has been described with particular reference to certain specific structural embodiments, it will be understood that various modfications and equivalent structures may be restorted to without departing from the scope of the invention as defined in the appended claims.

I claim:

1. In combination, a shaft having an end portion of circular cross section and bearing means for rotatably supporting the shaft for operation in a liquid bath, said bearing means comprising a circular hearing member surrounding the end portion of the shaft in radially spaced relation therefrom, and a plurality of flat-surfaced hard non-resilient bearing elements rigidly supported in said hearing member and operatively engaging the curved surface of said end portion at circumferentially spaced points and in substantially line contact therewith, the remainder of said bearing member being spaced from the end portion of the shaft to permit free liquid flow through the hearing member and the contact surfaces of said bearing elements being provided with a plurality of grooves extending at an angle to the axis of rotation of said shaft to facilitate washing away of foreign matter and thereby prevent accumulation of the same in pockets formed at the bearin g contact areas.

2. In combination, a roll for operation in a liquid bath, a shaft extending rigidly from the end of said roll and having a shoulder portion and an end portion of reduced diameter, a bearing sleeve surrounding said end portion of said shaft in radially spaced relation therefrom, a plurality of radial hearing elements in the form of elongated flat-surfaced bars of hearing material rigidly supported by said sleeve and operatively engaging said end portion at circumferentially spaced points and in substantially line contact therewith, the remainder of said sleeve being spaced radially outwardly from the shaft end portion and the hearing elements and having open unobstructed aXial ends whereby to provide enlarged unrestricted spaces between the sleeve and the end portion of the shaft, said spaces having substantially unobstructed flow communication With said liquid bath for permitting free liquid flow axially through the sleeve, and a thrust ring operatively secured to the reduced end portion of said shaft in abutment with said shoulder portion, said bars extending axially beyond the inner end of said sleeve for thrust bearing contact with said ring.

3. In combination, a roll having a shaft extendng rigidly from the opposite ends of said roll, an elongated strip of material extending below and around the roll for movement thereunder with the strip in tension whereby said roll and shaft tend to be lifted upwardly, and bearing means at the ends of the roll for rotatably supporting said shaft for operation in a liquid bath, said bear'- ing means eomprising a hearing sleeve surrounding the end portion of said shaft in radially spaced relation therefrom, a plurality of flat-surfaced radial bearing elements rigidly supported by said sleeve for engaging the shaft at circumferentially spaced points and in substantially line contact therewith, the remainder of said sleeve being spaced radially outwardly from the shaft and the bearing elements and having open unobstructed axial ends whereby to provide enlarged unrestricted spaces between the sleeve and the shaft, said spaces having substantially unobstructed flow communication with said liquid bath for permitting free liquid flow aXially through the sleeve, and at least two of said hearing elements being disposed along the upper circumference of said shaft with at least one other of said elements being at the bottom of the shaft whereby said shaft is adapted to be lifted from the bottom bearing element into bearing engagement with the upper bearing elements when the strip is in tension and whereby said shaft is adapted to rest on the bottom bearing element in spaced relation from the upper bearing elements when the tension of the strip is relaxed.

4. Bearing means of the class described for operation in a liquid bath comprising a bearing sleeve adapted to surround a shaft of circular cross-section in radially spaced relation therefrom, and a plurality of radial hearing elements in the form of elongated axially extending flatsurfaced bars of hard non-resilient bearin g material rigidly supported in said sleeve and having outer contact surfaces adapted to engage the curved surface of the shaft at circumferentially spaced points and in substantially line contact therewith, the remainder of said sleeve being spaced radially outwardly from the hearing elements and having open unobstructed aXial ends whereby to provide enlarged unrestricted spaces, between the sleeve and the shaft, said spaces having substantially unobstructed flow communication with said liquid bath for permitting free liquid flow axially through the sleeve, and the contact surfaces of said bars being provided with a plurality of grooves eX- tending at an angle to the aXis of said sleeve to facilitate washing away of foreign matter and thereby prevent accurnulation of the same in the hearing contact areas.

5. In combination, a roll for operation. in a liquid bath, a shaft extending rigidly from the end of said roll, a bearing sleeve surrounding said shaft in radially spaced relation therefrom, and a plurality of radial hearing elements in the form of elongated aXially extendling flat-surfaced bars of bearing material rigidly supported in said sleeve and operatively engaging said shaft at circumferentially spaced points and in substantially line contact therewith, the remainder of said sleeve being spaced radially outwardly from the shaft and the hearing elements and having open unobstructed aXial ends whereby to provide enlarged unrestricted spaces between the sleeve and the shaft, said spaces having substantially unobstructed flow communication with said liquid bath for permitting free liquid flow axially through the sleeve, and said bars extending aXially beyond the inner end of said sleeve whereby the projecting ends of said bars provide thrust hearing means for operative coaction with the adjacent end of said roll.

References Cited in the file of this patent UNITED STATES PATENTS %3,296 Junggren July 5, 1910 1,797,223 Anns Mar. 24, 1931 2,145,623 Hill Jan. 31, 1939 2,318,114 Tichvinsky May 4, 1943 2,335,800 Sheperdson Nov. 30, 1943 2,663,599 MacKay Dec. 22, 1953 FOREIGN PATENTS 214,679 Switzerland May 15, 1941 589,534 Germany Dec. 8, 1933 723,305 Germany Aug. 1, 1942

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