US1771769A - Taper and the art of mounting this - Google Patents

Description

July 29, 1930.v H. E. BRUNNER 1,771,769

TAPER AND THE ART OF MOUNTING THIS I Original Filed Sept. 12, 1925 INVENTOR Harald if. Bra/mar HIS ATTORNEY l atented July 29, 1930 UNITED STATES PATENT OFFICE.

HAROLD n. BRUNNER, or LARCHMONT, Nnw Yon-K, ASSIGNOR 'ro'rrrn sxAYEF BALL BEARING COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECT- if TAPER AND THE ART OF MOUNTING THIS Application filed September 12, 1925, Serial No. 56,096. Renewed June 12, 1929 This invention relates to mounting taper member-s in tap-er sockets, and has for an ob- ]ect to insure unlform distribution of normal pressure on the tapered surfaces to avoid loosening under lateral and radial stresses or both in combination. This result is accomplished by forming the taper on the tang, sleeve, or other member for insertion, of less angle than that of the receiving bore or socket, whereby, after the parts are coupled, upon the application to the male member of a predetermined force or drivingpressure its tapered outer surface engagesthe entire inner tapered surface of the female member uniformly expanding thelatter throughout its width. The leading end of the driven part takes up first andahead of the following endin establishing the fit.

In the drawings one practical application of the invention is illustrated, in which draw- Figure 1 shows in central longitudinal section a form of my invention applied to the journal of a railway car axle, illustrating the initial stages of application.

Fig. 2 is a view correspondng to the upper portion of Figure 1 showing the parts in assembled position, and 8 Figs. 3 and 4 are details illustrating some of the principles upon which my invention is based.

It is a well known fact that a bar, 5, subjected to compression as per Fig. 3, will shorten and expand laterally as indicated by dotted lines 6. This lateral expansion, assuming the same longitudinal unit stress,is proportional with the diameter of the bar, and proportional with the unit stress at a given diameter.

It is Obvious that a wedge, 7, Fig. 4, whose initial taper angle exactly equals the taper of the corresponding V shaped opening in the block, 8, under axial pressure, will expand laterally in a similar fashion as the straight bar, Fig. 3. Disregarding, as a first consideration, the forces acting on the tapered sides, pressure applied at the wide end would propagate over the whole length of the wedge resulting in stresses inversely proportional with the breadth of the wedge. Since the lateral expansion is proportional with the breadth and inversely proportional with the longitudinal stresses, the lateral expansion would be the same at any point, and the wedge angle would remain unchanged. Due to the fact, however, that under pressure, both the longitudinal component Of the lateral squeeze of the walls and the friction, will reduce the longitudinal stresses toward the narrow end, theexpansion at the wide end will be greater than at the narrow end, consequently the originally plain surface will be curved. Under these conditions the lateral pressure cannot be uniform but it is greater at the top and smaller at the bottom. The longer the wedge, the more pronounced this difference must be.

It is evident that a wedgewhich is held tight at the wide'end, and loose or slightly supportedat the narrow end is liable to loosen under the action of incidental lateralforces. To partly or totally overcome this efi'ect, the initial shape of the wedge should be such as to counteract the excessive expansion at the top, described above. Since it is both expensive and diflicult to machine the sides of a-wedge according to a curve, it would be more practical to compensate distortion under load by simply reducing the wedge angle of the plain surfaces by asuitable amount, determined by calculation, experiment or-both, which would result in an approximately uniform distribution of normal surface pressure. 7

Similar reasoning may be applied to a con.- ical sleeve, such as is used in firmly securing the inner races of ballor roller bearings on cylindrical, shafts. Such .a sleeve is illustrated in Figs. 1 and 2. Its fit under load The dif- 1 exaggerated for the purpose of illustration, since in practice in mounting a bearing considerably larger than that illustrated the difference in taper would be so slight that it would be practically impossible to represent it with pen and ink, this difference at the larger ends of the tapers being in micrometer dimensions of probably not more than one or two thousandths of an inch. The difference of cone angle is in the order of magnitude of one minute. This, however, is sufficiently great to effect a secure seating of the wedge, that is, the taper adapter sleeve, 11, into the bore of the ring, 10. r

The parts are shown fully seated in Fig. 2 and the ring, 10, is shown uniformly ex panded throughout its width. he dotted line, 20, illustrating the position occupied by the outer perimeter, 21, in the unassembled Fig. 1 position line 22 in Fig. 2 illustrating the expanded position of the outer perimeter of this ring. In this latter connection it must also be observed that the degree of expansion hasbeen exaggerated for the purpose of illustration since this expansion also will be measured by micrometer dimensions.

In mounting the device of course it is to be understood that the bore or inner surface of the adapter sleeve, 11, will be firmly supported. In the illustration the ring, 10, of the anti-friction bearing is to be mounted upon a car axle, 15, which usually in practice has a reduced journal, 16, there being a shoulder, 17, between this reduced portion and the main body of the axle serving as an abutment for a collar, 18, which engages the inner side of the ring, 10, and preventing'its inward movement during the seating of the wedge. A nut, 19, is shown mounted upon the screw threaded end, 150, of the axle for engaging the end of the adapter sleeve and forcing this into the bore of the ring, 10. According to prevailing practice the antifriction bearing rings, adapter, sleeves, and the journals of car axles are formed of hard, tough, elastic, homogeneous material, generally ferrous alloys, the alloys for the respective members usually differing one from the others and each part being heat treated according to its intended use and the character of its alloy. It will be seen that the parts are so' proportioned that the initial engagement between the ring and the adapter sleeve iswell toward the portion of the bore of the smaller meter, the point of engagement being represented at about the region indicated by the reference character, 14. This is for the purpose of economy since it is quite obvious that a much longer adapter sleeve may be employed which would initially extend through the bearing ring before there was engagee ment between the parts.

It is to be understood that the illustrated example of my invention discloses one form only, and that changes in detail may be made as occasion demands within the scope of the claims without departing from the spirit of the invention.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. In the mounting of taper members in taper sockets. the combination with a mem: ber having a tapered receiving bore or socket, of a member for insertion in such bore of sufficiently less cone angle than the cone angle of the bore that upon the insertion of such member into the said bore of the receiving member and the application of a predetermined force or driving pressure the tapered outer surface of the inserted member engages {)he entire inner surface of the receiving mem- 2. The combination with a ring having a tapered bore, of an adapter sleeve for entering such bore and having its outer surface tapered at a less cone angle than the cone angle of such bore and so proportioned that the initial engagement between such tapered surfaces is at the region of the smallest diameter of both, the parts being so proportioned that upon the application to the sleeve of a predetermined driving pressure the tapered outer surface thereof engages the entire tapered surface of the bore. 3. The combination with a ring having a tapered bore, of a shaft disposed in such bore, and an adapter sleeve for embracing the shaft and entering such bore and having its outer surface formed on a taper of a less cone angle than the cone angle of such bore and so pro portioned that the initial engagement between such tapered surfaces is at the region of the smallest diameter of both, whereby upon the application to the sleeve of a predetermined driving pressure the tapered outer surface thereof engages the entire tapered surface of the bore and uniformly expands the ring throughout its width.

{1. In the mounting of taper members in taper sockets, the combination with a member having a tapered-receiving bore or socket, these members being formed of hard, tough, elastic, homogeneous material, of a member constructed for partial free insertion into such bore, the taper angle of the inner member being so proportioned relatively to the taper angle of the outer member that upon application of the driving pressure necessary for establishing the fit, the elastic deformation sustained by one of the members willresult in a substantially uniform contact throughout its length with the tapered surface of the other member.

5. The combination with a ring, a shaft and an adapter sleeve'each formed of hard, tough, elastic, homogeneous material, the ring having a tapered bore, said shaft being disposed in such bore, and the adapter sleeve embracing the shaft and constructed to partially freely enter such bore and having its outer surface formed on a taper of a cone an- 1 gle differing from the cone angle of such bore, whereby upon the application to one of the members of a predetermined driving pressure the elastic deformation sustained establishes a uniform contact between the members throughout their length.

6. In the mounting of taper members in taper sockets, the combination with a taper member having a tapered receiving bore or socket, of an inner member constructed for partial free insertion into such bore,tthese members being formed of hard, tough, elastic, homogeneous material, one of such members having a face for receiving the application of a driving pressure, the taper angles of the members being so relatively proportioned that their region of initial engagement is at the

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