US3500671A - Rolling apparatus for manufacturing rings - Google Patents

Description

March 17, 1970 TADASHI sArro ETAL 3,500,671

ROLLING APPARATUS FOR MANUFACTURING RINGS Filed Feb; 23, 1968 5 Sheets-Sheet 1 March 17, 1970 TADASHI sArro mm 3.50

ROLLING APPARATUS FOR MANUFACTURING RINGS 3 Sheets-Sheet 2 Filed Feb. 23, 1968 March 17, 1970 TADASHI SAITO ETAI- 3,500,571

ROLLING APPARATUS FOR MANUFACTURING RINGS Filed Feb. 23, 1968 3 Sheets-Sheet 5 PI'BSSILYE.

United States Patent ABSTRACT OF THE DISCLOSURE A rolling apparatus for manufacturing rings comprises a pair of inclined rolling rollers, a pair of travelling members respectively supporting the rolling rollers and V a roll block supporter carrying a group of rolls on each of its side surfaces. Through the travel of the travelling members, the rolling rollers are adapted to move close to or away from each other. The rolling rollers press a material ring cooperatively with the group of rolls, and

a series of rolling operation is continuously performed through the rotation of the roll block supporter which rotates intermittingly every 90 degrees.

The present invention relates to a rolling apparatus for manufacturing rings such as outer and inner races of bearings, rings in spinning machines and the like, more particularly, the present invention relates to the rolling apparatus developed by utilizing the invention disclosed in the Patent Gazette of the US. Patent No. 3,230,606 registered Jan. 25, 1966.

In general, with the progress of machine civilization, there has been an unlimited demand for improved precision and cost reduction with respect to mechanical parts such as bearings which are indispensable to the mechanical structure. However, since the outer races and inner races of bearings are relatively simple in structure, it is at present generally considered that they have been developed to an utmost extent that there is no room for improvement with regard to economical and effective use of the material and to the method of production.

The present invention contemplates providing for further improvements in the method of manufacturing bearings to thereby achieve a marked reduction in the cost of material and of machining. A principal object of the present invention is therefore to provide an apparatus which is capable of manufacturing high precision races from minimum amount of material in a continuous and rapid rolling method.

Other objects and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings, in which:

FIG. 1 is a front view partially in cross section showing a rolling apparatus of the present invention;

FIG. 2 is a view in cross section taken along the line 22 in FIG. 1, showing a rolling apparatus of the present invention;

FIG. 3 is a front view on an enlarged scale showing main roller portions in the apparatus of the present invention;

FIG. 4 is a part diagrammatic and part sectional view of a pressure control system in an inner roller according to the present invention;

FIG. 5 is a graph showing the most desirable mode of the variation of the pressure which is exerted by the inner roller on a race to be rolled;

FIGS. 6A and 6B are a view showing examples of the outer races and inner races of a ball bearing and a roller bearing to be manufactured by the apparatus of the present invention;

FIGS. 7A and 7B show the outer races of a ball bearing and of a roller bearing manufactured by the apparatus of the present invention, the virtual line showing rings finished by being ground; and

FIGS. 8A and 8B show the outer races of a ball hearing and of a roller hearing which races are formed by a ring rolling apparatus of a conventional type, the virtual line in the figure showing finished races obtained by shaping and chamfering on a lathe and by grinding with a grinder.

Now referring to FIGS. 1 and 2, roller supporting members 1 supporting rolling rollers (to be later described) are respectively mounted on a pair of rails 3 in vertically slidable manner, said rails being suitably spaced apart and disposed in a vertical direction in the upper front portion of a main frame 2. Upwardly extending from the upper side portions of the roller supporting members 1 are bolts 4 passing in screwed engagement through supporting members 5 which are, secured integrally to .the upper end portion of the main frame 2, the bolts 4 thus holding the roller supporting members 1. The upper end of each bolt 4 is provided with a handle 6. By turning the handles 6 the roller sup porting members 1 can be adjusted to a desired position. Travelling members 8 carrying roller shafts 7 therein are respectively mounted on each of the roller supporting members 1, which travelling members are adapted to travel in the lateral direction in which said travelling members 8 face each other. This movement is ordinarily effected by means of cylinders 9 and plungers 10 which are operated by oil pressure or some other suitable source of pressure, and the range of the travel is limited by forward travel stoppers 14 and backward travel stoppers 15.

The roller shafts 7 carrying the main rollers 11 at the one end portion are supported by the travelling members 8 with inclination so that said end portions mounted main rollers 11 may be disposed in the upper position, whereby the main rollers 11 on the end portions of the right and left roller shafts 7 can be brought into contact with each other only at the lower portions. Thus, a pair of the main rollers 11 forms a channel-like shape b which is to press the peripheral surface 12 and opposite side surfaces 13 of the race a to be rolled (see FIG. 3). Disposed through the central portion of the main frame 2 is an inclined forked lever 34 having the rear end pivotally attached to the main frame 2 at a portion 16 and the forward end provided with a lateral axis 17. On the lateral axis 17 is mounted a roller block supporter 18 of a square section which is adapted to be rotated intermittently every degrees by a drive system provided with a thermometer or hydraulic force (not, shown in figures), each side surface of the roll block supporter 18 being provided with a group of rollers which are rotatably mounted 'by means of a holding member 19 having an angular cross section. The group of rollers comprises a plurality of supporting rollers 20 disposed in conformity with the curvature of the outer peripheral surface of a race a to be rolled and an inner'roller 21 serving to support the race a. Although a detailed figured representation is herein omitted, the length of each of the arms 31 supporting each of said rollers 20 is adapted to be elongated or shortened by providing a screw or the like in the intermediate portion thereof so that the. position of each roller may be adjusted as desired in accordance with the diameter of the race to be rolled. The lat eral axis 17 on which the block supporter 18 is mounted is supported by a movable arm 24 which is provided with a cylinder 22, plunger 23 and receiving member 25 held to the lower portion of the main frame 2. Through the cooperative support of the arm 24 and aforementioned lever34, the lateral axis 17 and roller block supporter l8 can strictly be held in position, while by operating the plunger 23 they can also be adjusted to an upper or iower position. g Now the operation of rolling races in accordance with he present invention and the effect thereby achieved will be described. In FIG. 2 an annular material a to be shaped by rolling is placed on the inner roller 21 in the group -o'f rollers positioned at A, and then the roller jalocksupporter 18 is rotated 90 degrees to a position B by a suitable power source (not shown in the figure), whereuponthe roller block supporter 18 is elevated verically by actuating the plunger 23. Simultaneously with the positioning of the material thus raised to a p'redeter' nined position, the plungers 10 are operated to bring a. pair; of the main rollers 11 closer toward each other which are set apart formerly (see FIG. 1). The main .ollers 11 in this condition are then set in rotation by anothersuitable power source through the roller shafts 7, gears 26 and 27, and pulleys 28. In this way, the annular material a is rolled in desired dimensions cooperatively with'the main rollers 11, inner roller 21 and supporting rollers 20. Toward the end of this rolling operation, the pressure'of the inner rollers against the material is gradually decreased during the additional rolling step following tothe' first rolling step. FIG. 5 is a graph showing the most desirable mode of the variation of the pressure which isexerted by the inner roller on a race to be rolled. It is contemplated that after the rolling operation is carried out for a period t in the figure i.e. during the first rolling step the pressure is gradually, during the additional step, decreased to be reduced to zero at the final stage e of the rolling operation. This pressure control system is generally shown in FIG. 4, in which on the surface of an annular plate 36 driven by an electric motor 35 there is mounted a cam 37 formed in accordance with the shape of the graph in FIG. 5. And the pressure of the plunger 23 against the inner roller 21 is adapted to be controlled corresponding to the shape of the cam 37.

Since the product thus rolled is tightly held in the channel-like shape formed by a pair of the main rollers 11, marring or deformation would possibly be caused in its side surfaces, if the product held in this manner should be taken out as it is. Therefore, in accordance with the present invention, the travelling members 8 each carrying the main roller 11 are moved away from each other by actuating the cylinder 9, whereby the product can be readily released from the main. rollers. The roller block method, a ring as shown in FIGS. 8A and 8B having an allowance 29 for shaping onzfa lathe and draft taper 18 for release from the rollers is at first shaped with a ring rolling machine and then it is further shaped on a lathe in the dimensions having a final'finishing'allowance'of about 0.1 to 0.15 millimeter in thickness. Thereafter hardened by heating, the workpiece is finished by being ground with a grinder in desired dimensions. The conventional method, therefore, requires excess amount of material, namely the material for' the cutting allowance, finishing allowance anddraft. taper B as described above. Moreover, the above-mentioned steps involved therein are complicated and take much timeto carry out.

As a result, the products obtained are relatively expensive. Onthe other hand, the'rolling operation in accordance with the present inventionvis cooperatively performed by a pairof the: aforementioned main rollers and group of rollers supporting the workpiece, and the main rollers are moved away from each-other in order to release the rolled products, so that races can be rolled effectively with high speed and precision. There is accordingly no necessity of leaving anallowance for lathe working, but the workpiecexcanbe formed in minimum (ll? mensions with a slight finishingallowance 30 for grinding with .a grinder; a marked reduction in the cost of material and of machining can be accomplished.

Furthermore, in order to form along the outer peripheral edges the chamfers 32 (see FIGS; 7A and 7B) which are indispensable to bearings, each workpiece is, according to a conventional method, mounted on the lathe for shaping, and therefore the complicated works involved result in so much cost increase. Since the present invention enables a .pair of the main rollers and the roller group to cooperatively carry out high precision rolling; chamfering can be dispensed with by providing in advance themain rollers with a shape conforming to the chamfers of finished dimensions. Thus,-as compared with the conaforementioned is ,nolonger lost, which helps to bring supporter 18 is then turned 90 degrees, the product, to-

gether with the group of the rollers, thereby being carried to a position C, where it is taken out from the roller group. Upon the roller block supporter 18 being further rotated 90 degrees to a position D, the group of rollers now carrying no workpiece is cooled by cooling liquid, air or the like which is discharged from a nozzle 33.

By rotating the roller block supporter 18 intermittently every 90 degrees, thus carried out is one cycle of the operation which comprises feeding a material at a position A, rolling at a position B, removing the product at a position C and cooling the mechanism at a position D. Each step of the operation described above is performed at positions A, B, C and D simultaneously and respectively, producing four finished workpieces during one cycle of the operation. Therefore, in manufacturing races by rolling operation, it has become possible to reduce the time required for handling such works as feeding and removal of a material, cooling of the apparatus and the like; a marked improvement of the manufacturing effi ciencyhas accordingly been attained.

' It will readily be understood that, as compared 'with a conventional rolling method for forming races, the apthe material cost down.'As a result, products are, on the whole, made obtainable at substantially low cost and with high precision.

In addition, because the main rollers in the present invention are constructed in such a manner that they can be brought close to or away from each other, it has become possible to manufacture a race having no draft taper but perfectly parallel side surfaces or a race having side surfaces tapering in section the width along the outer diameter thereof being smaller than that of the inner diameter, while by suitably modifying the shape of the main rollers, a ring of a flange-shaped section or of some other complicated cross section can be manufactured. These are remarkable advantages achieved by the present invention. Furthermore, when heat forming is performed under a heavy load, heat transference and generation cause heating of the apparatus, further .creating wear therein and impaired precision as well as greatly shortening the-service life. However, since the present method involves adequate cooling operation provided at position D, these disadvantages have been overcome notwithstanding the continuous rolling operation, and remarkably efficient and high precision operation can be secured over a long period. Although the present invention has been described with respect to a typical embodiment, the inventors do not wish to limit the invention only to the embodiment, but it is to be understood that the invention may also reside in all of the substitutes, equivalents and alterations without departing from theprinciple of the present invention and the spirit of the inventors as set forth in the claims stated hereinafter.

What we claim is:

1. A rolling apparatus for manufacturing rings comprising a pair of inclined main rollers cooperatively pressing the peripheral surface and side surfaces of an annular ring to be rolled, a pair of travelling members respectively supporting each of said main rollers and mounted on each of supporting members so as to be slidably moved by an oil pressure device or some other suitable pressure source in a direction in which said rollers face each other, and a roller block supporter of square cross section, each side surface of said roller block supporter being provided with a group of rollers supporting an annular material to be rolled by pressing said material cooperatively with said main rollers, said roller block supporter being adapted to be rotated intermittently every 90 degrees by a suitable power source.

2. A rolling apparatus as claimed in claim 1, wherein said roller block supporter is supported by a lateral axis passing through the central portion thereof, said lateral axis being strictly held in position cooperatively by a lever obliquely crossing the central portion of a main frame and by a movable supporting arm upwardly extending from the lower portion of the main frame, said supporting arm being provided intermediately therein with a cylinder having a plunger whereby said lateral axis and roller block supporter are permitted to move vertically.

' 3. A rolling apparatus as claimed in claim 1, wherein said supporting members respectively supporting each of said travelling members are each mounted on a pair of rails in vertically slidable manner, said rails being suitably spaced apart and disposed in a vertical direction in the upper front portion of the main frame, said supporting members being adapted to be placed at a desired position by means of adjusting bolts or other means whereby the position of said main rollers can be vertically adjusted in accordance with the size of the material to be rolled.

4. A rolling apparatus as claimed in claim 1, wherein said group of rollers disposed on each side surface of said roller block supporter comprises an inner roller supporting the material to be rolled and a plurality of supporting rollers disposed in conformity with the curvature of the outer peripheral surface of the material.

5. A rolling apparatus as claimed in claim 4, wherein the length of each arm supporting each of said supporting rollers in the roller group is made adjustable by providing a screw or the like intermediately therein so that the position of each roller may be adjusted in accordance with the diameter of the annular material to be rolled.

References Cited UNITED STATES PATENTS 1,781,140 11/1930 Taylor 7287 3,230,606 1/1966 Saito et a1 29-148.4

MILTON S. MEHR, Primary Examiner S. W. WEINRIEB, Assistant Examiner US. Cl. X.R.

3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,500y67]. Dated March 17,

Inventor-(s) Tadashi Saito, Masaya Saito, Masaru Saito and Hachiro Saito It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column 5, line 13, change "by" to and.

SIG NED AND SEALED JUL 141970 4 Attest:

Edward Fletcher In WILLIAM E. sum, .13. Att fi g Officm' Gomissioner of latents

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