US2401810A - Rolling motion generating gearing for grinding machines and testing apparatus for bevel wheels - Google Patents

Description

June 11, 1946. A. ,AEPPLI ROLLING MOTION GENERATING GEARING FOR GRINDING MACHINES AND TESTING APPARATUS FOR' BEVEL WHEELS Filed Dec. 6, 1943 s Sheets-Sheet 1 vJume 11, 1946. AEPPL; 2,401,$1@

ROLLING MOTION GENERATING GEARING FOR GRINDING MACHINES AND TESTING APPARATUS FOR BEVEL WHEELS Filed Dec. 6, 1943 5 Sheets-Sheet 2 v 2 2A 25 Q a 26 June 11, 1946. A. AEPPLI 2,401,810

ROLLING MOTION GENERATING GEARING FOR GRINDING MACHINES AND TESTING APPARATUS ,FOR BEVEL WHEELS Filed Dec. 6, 1943 3 Sheets-Sheet 3 fzz'merziorr Patented June 11, 1946 ROLLING MOTION GENERATING GEARING FOR GRINDING MACHINES AND TESTING APPARATUS FOR BEVEL WHEELS Albert Aeppli, Zurich, Switzerland, assignor to Maag-Zahurader und-Maschinen Aktiengesellschaft, Zurich, Switzerland Application December 6, 1943, Serial No. 513,105 In Germany July 4, 1942 4 Claims. 1

This invention relates to rolling motion generating gearings for grinding machines and testing apparatus for bevel Wheels.

For rolling motion generating gearings for machine tools for machining gear wheels, more particularly gearings of this kind intended for use in connection with testing apparatus, extremely high precision of operation is required.

This can be expected only if the working parts thereof are manufactured with utmost accuracy, said parts are few in number and the connections between them are of high grade efficacy.

The rolling motion generating gearing accord ing to the present invention is characterized in that in it the two rotational movements of which the rolling motion of a cone can be composed, that is, the rotational movement about the axis passing through the apex of the cone of the imaginary plane wheel and that about the axis of the cone are converted in such manner that said rotational movements are no longer performed about intersecting but about parallel axes by which means said movements can be combined with each other in simplest manner at shortest axle spacings with the aid of known means so as to realise the obtainment of a relation between both rotational movements resulting in the form of a ratio of diameters of cylindrical transmission members.

Several embodiments of the present invention are illustrated, by way of example only, in the accompanying drawings in which Fig. 1 shows a schematic elevation of the working parts of the rolling motion generating gearing according to the invention;

Fig. 2 is a corresponding top plan View;

Fig. 3 shows a side elevation;

Fig. 4 shows an elevation of a modified embodiment of the gearing;

Fig. 5 is a side elevation of Fig. 4;

Fig. 6 shows an elevation of a third embodiment of the invention;

Fig. 7 is a view of a modified detail of Fig. 1;

Fig. 8 is a top plan view corresponding to Fig. 7;

Fig. 9 shows an elevation of the gearing schematically illustrated in Fig. 1;

Fig. 10 is a top plan view corresponding to Fig. 9, and

Fig. 11 is a side elevation corresponding to Fig. 9.

In the drawings numeral I indicates the work piece of which a bevel gear is to be formed shown in working position in the machine.

Referring to Fig. 9, a bed carries a vertical pin 2| and serves as a mounting for a turntable 22 which is guided by said pin and an intervening ball bearing, the table 22 being integral with a standard 8. In two vertical relatively opposed walls of this standard eye bearings 23 are arranged the common axis of which intersects the extended axis of pin 2| at right angles thereto. In these eye bearings are mounted the arms 24 of a swing 9 in which a work spindle 25 is mounted. The extended axis of this spindle intersects that of the eye bearings 23 perpendicularly as well as the extended axis of the pin 2|. The swing 9 can be inclinedly adjusted to the axis of the pin 2|. To this end the swing is provided with laterally extending studs 26 which project through arcuate slots 2'! in the walls of the standard 8 and carry clamping nuts 28.

On the turntable 22 a Worm wheel segment 29 is fastened into which meshes a worm 30 mounted in the bed 20. This worm is rotated in opposite directions by means of a gearing not posably roll if it is to be ground on the rolling motion principle. The two axes x and y intersect each other at the cone apex S (Fig. 1). With the spindle 25 a rolling cylinder 2 is firmly connected which in turn is coupled through tapes 3, 4 with a cylinder 6 mounted on a countershaft 5 (Fig. 2). The shaft 5 is mounted in the swing 9 so as to extend horizontally underneath the spindle 25 and crossing it'at an angle of The tapes 3 and 4 function in the manner of a crossed belt drive.

Said tapes extend between the two cylinders 2 and 6 at right angles to their axes and parallel with each other so as to couple these cylinders for common rotation devoid of play. A rolling cylinder 1 is sustained by the pin 2| with its axis yremaining stationary. On the standard 8 (Fig. 9) is further rotatably arranged a horizontal counterdrive shaft ill (see also Fig. 1) on which a cylinder is mounted. This cylinder is connected with a rolling cylinder 7 through tapes 3| in the fashion of a crossed belt drive. The tapes 3|,therefore, extend between the two cylinders I and H at right angles to the axes thereof and in parallelism with each other.

The shafts and iii carry on their outer ends belt pulleys i3 and I2, respectively, about which a steel tape [4, 1-5 is passed. In order to prevent expansion of this steel tape as much as possible in the rectilinear sections thereof strips 3| of greater strength are included.

During the swinging movement; of thetur-n table 22 the tapes l4, l5 beingalternatelywound on and off the cylinder 1 impart rotative-move-- ment to the cylinder I l which movement is transmitted by the tapes l4, l5 to the shaft 5'which in turn rotates the work spindle =25; The-ratio of the two rotational movements, that is, the one about the axis y to that about theaaxis a:, which ratio should be equal to sin a (Fig. 1), mustibe' i equal to the relation between the cylinder diam! eters cites In Figs; 4"and"5 "a modified form of 'the gearing is shown. In this'arrangement the shafts 5 and are mount'ed in the "same manner *as precedingly described; They are; however, not coupledby steel tapes such-as 4 and l51butby an arcuate sector; It 1 which. is swingably mounted coaxiall with'the eye bearings'23 andi -coupled to cylindrical discs" HZ; Il3-that are-secured-to=the' shafts band Illrespectivelybyrrolling-tapes I M,

In Fig. 6 a further embodiment" of the invention is shown in which the swingable sector- Itshown in Fig; 4*is' replaced by-a bar-2| which is displace-able in its longitudinal direction and-e'to which rolling :bands -;l M; H 5 are "fastened.

In'Figs: 7 and'8 'parts'of another modificationare shown. In this" arrangement the spindle 2-5 carrying the 'work I andthe'shafti are so-mounted in the swing 9 as to lie in"a--common: plane passing through the axis of rotation of the swing. They are coupled to eachother for cornmonsrotation by a" rack lfr'which slides inthe swing fi-perpendicularl to this plane andmeshes in spur gears 11,- I8 which are secured -tothe spindle 25 and the shaft :5'respectively. This-arrangement presents, in distinction from a possible mode of "coupling the two: shafts 5'an'd 25 by means of bevel wheels; the advantage that the spur gear tooth systems used-c-an'be manufactured more'pr'eciselytotrueform: A-similar operative connection forthegearing being comthegrinding disc is retractedfrom'the tooth gap having been ma'chinedina known manner, the

relative rolling motion" is reversed and the rolling motion generating gearing restored into initial position. During the restoring movement" the work is revolubly advanced for one tooth division, whereupon the "rolling movement is reversed into the working direction again and the working tool is further applied to the work in which way a fresh working operation is initiated. The machine may also be constructed so as to be able to further machine the same-tooth flanks also duringthe-backward rolling motion and divides only at the end of the cycle of rolling operations or'divides on the completion of the traverse performed b rolling forwardly and grinds the tooth flankof anothertooth gap while rolling backwardly;

Eevel wheel grinding machines for which,

above all, extreme accuracy of the product is required are to be equipped with a rolling motion generating device as shown in Figs. 1-6 and 9-11.

Those machines, however, can be equipped with a rolling1motion generating device as shown in Figs. '7 and 8 for which maximum possible precision is not required but instead an amount of production as great as possible such as conventional inwhat may be termed-singb use -or special Working tools which serve only one purpose and in which only a'few-sizes of Wheels are machined by quantity production and the gear teeth of the gearing are required to be ground into accurately true form.

Bevel wheels of accurate'configuration produced in themanner hereinbefore described may be used=for making bevel wheel drives for substitution with connections between the axis wand the counterdrive shaft 5 on one hand'and bes I tween the axis y and theshaft ill on the' otl'ier. Theoretically an appropriate connection serving this purpose may also consist in ascrew wheel drive having crossed axles, Howeven'such drives scarcely enter into the question due topremature wear on the gear teeth owing to point bearing engagement between cooperating te'eth.

For testing apparatus only the tape-connection between cylinders as described enters' into -the' For suchapparatus a testing feeler question.

member is substituted for the grinding disc.

The grinding "disc 32'indicated 'in Fig, 1 describes with its grinding edge aplane surface which coincides with the flank of an imaginary plane wheel extending coaxially-wi-th the-axis 11 perform a rolling movement.

I claim:

1. In a rolling motion generating'mechanism for grinding and testing bevel gears. a first member mounted to rotate about-an axis, a second member supported on the first member and mounted to rotate about another axis, which serves for holding the work, a pair, of counterdrive shafts parallel to each other respectively mounted perpendicularly relatively to the respective axes, rotary motion transmitting means conmeeting said countershafts, and rotary -motion transmitting means connecting the respective shafts with the respective members to whose axes they are mounted perpendicularly.

2. A rolling motion generating mechanism for grinding and testing bevel gears according. to claim 1, and a pair of cylinders respectively mounted on said countershafts, thetransmitting means between said shafts comprising, a'steel band operatively interconnecting said cylinders, and a pair of crossed bands opcrativel interconnecting said oylinclers and their respective'rotar members. I

3. A rolling motion generating mechanism for grinding and testing-bevel gears according to connecting the shafts with the respectivemem- On this flank the'work l is supposed to bers comprise cylinders mounted on said countershafts, and crossed bands interconnecting the cylinders with their respective rotatable members, the rotary motion transmitting means between the countershafts including a removable and replaceable ratio gearing.

4. A rolling motion generating mechanism for grinding and testing bevel gears according to claim 1, and in which the countershafts are provided with cylinders mounted thereon, and crossed bands interconnecting the cylinders with the respective members to whose axes they are mounted perpendicularly, the rotary motion transmitting means connecting the countershafts including speed ratio producing means for providing a speed ratio equal to that existing between the said two rotatable members.

ALBERT AEPPLI.

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