US1497274A - Splined gearing - Google Patents

Description

June 10, A19241. I 1,497,274

v W. G. HAWLEY SPLINED GEARING Filed March 25 1924 2 Sheets-Sheet l TTO www@

.Hume lo, 19%l 1,497,274

` l w. G. HAWLEY SPLINED GEARING 2 Sheets-Sheet 2 VWTNESSES slide axially along said shaft.

tP/etented .linie .lla-i924. l

Applicatioii'led March 25, 1924. Serial No. 701,706.

` To all whom it may concern: l

Be it known that I, WILLIAM G. HAwLEY, a citizen of the United States, and a resident of Elmira, county of Chemung, and State of New York, have invented certain new anduseful Improvements inI Splined Gearing, of which the following is a specification.

This invention relates to that class of gearing in which a gear is suitably mounted upon a shaft so that itmay be readily moved along said shaft but forced-to rotate therewit/h. Heretofore, this class of gearing has been constructed in Jvarious forms, each form having vits own peculiar drawback. Thus, in the use with a square shaft of a ear having a bore sufficiently free to permit it to slide axially thereon, it is slow, expensive and almost impossible to accurately grind the square hole in the gear hub for the purpose of correcting the distortion therein after said hub has been hardened. Tn another form a roundshaft and slidable gear are `both provided with milled or breached key-ways, a key being inserted in said keyways for holding the gear against rotation on the shaft but permitting said gear to This con-y struction is subject `to several drawbacks. The shaft is weakend by having key-ways cut therein. When the shaft is hardened by a heat treatment, these key-ways are distorted' and in consequence, when the keys are inserted, the hardened bearing surface on the shaft-is warped. Added to this is the fact that it is a -very diiicult if -not impossible operation to properly grind the key-ways of small gears like those used for automobiles, for example. It is desirable that the spline gear and the spline shaft shall have a 4truly cylindrical bearin one upon the other and also that these earing surfaces shall be hardened.

But the' process of hardening causes more or less distortion or warping of these cylindrical bearing surfaces, so that some expedient must be employed for overcoming this difiiculty with a view to producing a true cylindrical surface after hardening. Two

methods have been employed for this pur` pose, namely, one in which'the gear is made to lit uponthe outer diameter of the splines; and the other in which the gear takes its bearing upon the' portions between the splines. In the former method according to which the inner` bore of the gear was made to bear directly upon vthe top surfaces of the condition ofthe gears which slide thereon,`

secured. This is due mainly to the fact that the cylindrical portions of the bore in the hub of a gear, can be accurately ground under commercial conditions. The shaft can then be made to t the ground bore of the ear hub, by properly hardening and grin ing the cylindrical surface thereof.

This grinding operation, however, involvesl the use of peculiarly shaped grinding p wheels and the provision of specially designed devices for maintaining said grinding wheel in proper shape and in suitable relation to the -work while the operation is in regress.

ne of the provide an improved construction for spline shafts and gearsl in which true cylindrical objects of this invention is toA A,

bearing surfaces'v between shaft and gears may be secured' in a simple and eifectivey manner. f

Another object is to provide a variable speed transmission mechanism1 of improved construction and an improved l combination andrelation of parts therein whereby the transmission mechanism can be economically constructed aiid a high degree of precision obtained Vby the employment .of usual shop methods. Toward the attainment lof this object and as an adaptation of the principles underlying the present'invention, the embodiment shown on the drawings includes a spline shaft provided with integrally formed splines which have been hardened and afterwards round to a true cylindrical surface :over -t e top surfaces thereof. Mounted on this shaft and having its inwardly presented splines meshing with the splines on said shaft, is a gear which is provided with axially' spaced inserted bearings which have been machined, hardened and ground, prior to being inserted into said gear. The hardened and round inner cylindrical surfaces of these inserted bearings shown in e evation;

Figure 2 is an enlarged fragmentary portion of Figure 1 showing the spline shaft in elevation and certainA hub portions of the gear in section; f

Figure 3 A's a section on the line 3--3, Figure 2, parts being broken away and parts shown in elevation, and

Figure 4 is a section on the line 4-4, Figurev 2, parts being broken away -and parts shown in elevation.

Referring more particularly to the drawings, a housing 1, is provided at one end witha bearing casing 2. The drive shaft 3 which receives its power from the engine (not shown) is journalled in axially spaced ball bearings 4 and 5. The inner belled end 6fof the shaft 3 accommodates the ball bearings 7 for one end 8 of a spline shaft 9. The other end 8 of said spline shaft is journalledin ball bearings 10 adjacent the other end of the housing 1. Thebelled end 6 of shaft 3 is provided exteriorl'y with a rspur gear 11 permanently in mesh with a spur gear 12 keyed to the countershaft 13 by a key 14. The inner belled end of shaft 3 also carries an external spur gear 15 which is adapted to mesh with an internal spur gear 16 with which an axially movable gear 17 is provided. An exterior spur gear 18 with which the gear 17 is also provided, may

be thrown into and out of mesh with a s ur gear 19 bymeans of suitable gear shifting means (not shown) operating 1n a circular groove 20. Said gear 19 is keyed to the countershaft 13 by means of a key 21. Axially spaced from the gear 17 and internall meshin with the spline shaft, is a ble .gear llock 22 provided with a circular groove 23 in which suitable ear shifting mechanism may operate.- aid gear block comprises a larger spur gear 2li-and a smaller s ur gear 25, the former being adapted to e thrown into and out of mesh with a gear pinion 26 on the countershaft 13 and the latter being adapted to` be thrown into and out'of mesh with a spur gear 27 on the countershaft 13. By means of the above described gears, in connection with the variable driving connections thru the sliding spline gears, the usual selection of speeds may be made.

Mazara Referringvnow to Figures 2, 3 and 4, al

specific description of the spline gear connections between. the left-hand gear 22 and the spline shaft 9 will serve also for the corresponding connections between the rightgear and spline shaft as well as a suitablerconstruction of parts for enabling said bearing surfaces to be ground to a true cylindrical form after they have been hardened by a heat treatment. For this purpose, the top surfaces 33 of the splines 9, are turned, hardened and ground to a true cylindrical surface with respect to the axis o f spline shaft 3. This is a simple grinding operation which 'may Ybe conducted in the usual well known manner. In order to avoid the necessity for grinding the bottoms of the grooves in the bore of the gear, the hub of said ear, is provided with axially spaced cylin rical recesses 28 which may be readily machined and nished. Within said recesses are inserted bearing rings 29, which have been turned, hardened and ground to true cylindricalsurfaces before their installation in position to serve as axially spaced bear-,

ings for the hardened and ground top surfaces of the splines 9 on the spline shaft.` l

The grinding operation on the hardened bearing rings 29 isa.Y simple case of cylindrical grindm which ma be accomplished Without diilncu ty in a we l known manner. Suitable-means for releasably securin the cbearing'rings 29 in position within the ubs of gears 17 and 22, may be provided by springing wire rings 30 into suitable circular grooves 31 with which the cylindrical walls of recesses 28 are provided for this purpose. As shown in F1 ure 3, the ends of wire rings 30 are space apart and provided with' inwardl means of which said ringsvmay be contracted and withdrawn whenever it is desired to do so. The advantages of thisconstruction are obvious from the above description and briefly related are those resulting from a combination' and relation of elements which by reason of their simple form and freely \accessible bearing surfaces,

turned ends 32 by are adapted to be trued by a simple grinding operation after being hardened by a heat treatment for the purpose of securing a true bearing contact permitting an axial movement between a spline shaftand the 'gear in mesh therewith.

1 claim v 1. The combination with a spline shaft, of an internal gear meshing therewith, said gear being provided with inserted hardened and ground bearings in bearing contact'with corresponding bearing surfaces on said spline shaft.

2. The combination with a shaft provided with splines, of a gear having inwardly presented splines meshing therewith, and bearings separately finished and inserted into said gear, said inserted bearings having their inner surfaces bearing on the top' surfaces of said splines.

3. The combination with a shaft, of a. gear movable axially on said shaft but nonrotatably connected thereto, and bearings for said gear, said bearings being separately finished and applied to said gear.

4; The combination with a spline shaft, of a gear meshing therewith and movable ax ially thereof, and separately finished bearings inserted into said gear and bearing on the top surfaces of said splines.

5. The combination with a spline shaft of a gear non-rotatably mounted thereon but movable axially thereof, and separately finished-axially spaced bearings inserted in the bore of said gear.

6. The combination with a spline gear, of a gear non-rotatably mounted thereon. said gear being provided with recesses adjacent opposite ends of the bore'therein, and bearings inserted in said recesses, said bearings being providedl with inwardly presented bearing surfaces bearing on the top surfaces of said splines.'

'i'. The combination with a shaft provided with axially extending splines hardened and ground on the top surfaces of said splines, of an internal gear meshing with said splines and provided with axially spaced recesses in the bore thereof, and separat'ely hardened and ground bearing rings inserted in said recesses and bearing on the tops 'of said splines.

8. The combination with a shaft provided with axially extending splines hardened and ground on the top surfaces of said splines of an internal gear .meshing with said splines and provided with axially spaced recesses in the bore thereof, separately hardene-d and ground bearing rings inserted in said recesses and bearing on the tops of said ysplines and means for releasably securing said bearing rings in said recesses.

9. The combination of a hardened steel shaft with integral' splines having their outer peripheral bearing surfaces 'ound true with respect to the axis of sai shaft,

a gear in mesh with said splines and having inter-tooth spaces of larger diameter than said bearin surfaces and with axially spaced cylin rical recesses coaxial with said shaft, and hardened steel rings seated within said recesses and having inwardly presented bearing surfaces ground true with respect to the bearing surfaces on said splines.

10. The combination of a shaft with outwardly presented hardened splines provided with peripherally ground bearing surfaces trued with respect to the axis of said shaft, and a gear having axially spaced unbroken bearing surfaces hardened and ground true with respect to the bearing surfaces of said splines on which they bear.

11. The combination with a gear having axially spaced internal bearings which are hardened and cylindrically ground true with respect to the axis of said gear, of a shaft with outwardly presented splines with hardened outer peripheries cylindrically ground with respect to the axis of said'shaft andin slidable engagement with said bearings on the gear.

12. The combination of a hardened steel shaft with integral splines having their outer peripheral bearing surfaces ground true with respect to the axis of said shaft, a gear having axiallyspaced cylindrical recesses coaxial .with said shaft, and hardened' steel rings seated Within said recesses and having inwardly prentcd bearing surfaces ground true with respect to bearing surfaces on said splines.

13. The combination of a shaft with outwardly presented splines provided with hardened and ground top surfaces and a gear having an inner bore larger than the diameter of the shaft between said s lines and inwardly presented splines havmg a root diameter greater than the outer diameter of said splines on the shaft, and axially spaced bearing surfaces hardened and ground true with respect to the bearing surfaces of said splines on which they bear.

14. The combination with a gear having axially spaced internal bearings which are hardened and ground true with respect to the axis of said gear, of a shaft with outwardly presented bearing surfaces hardened and ground true with respect to said internal bearing on the gear, said ear being non-rotatably connected to said s aft.

WILLIAM G. HAWLEY.

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