US2392819A

US2392819A - Gear grinding machine

Info

Publication number: US2392819A
Application number: US519492A
Authority: US
Inventors: Ivor J Gruenberg; Samuel G Brady
Original assignee: GEAR GRINDING Co
Current assignee: GEAR GRINDING Co
Priority date: 1944-01-24
Filing date: 1944-01-24
Publication date: 1946-01-15
Anticipated expiration: 1963-01-15

Description

Jam 15, 1942;.

l. J. GRUENBERG ET AL GER GRINDING MACHINE Filed Jan. 24, 1944 2 Sheets-Sheet 1 ATIORNEY Jan. l5, 1946,

' l. J. GRUENBERG ET Al.

GEAR GRINDING MACHINE F'iled'Jan. 24, 1944 2 sheets-'sheet 2 INVENTORS I VOR J.GRUENBERG SAMUEL G.BRADY ATTORNEYS Patented Jan. l5, 1946 GEAR GRINDING MACHINE Ivor J. Gruenberg, Pleasant Ridge, and Samuel G. Brady, Royal Oak, Mich., assignors to The Gear Grinding Company, Hamtramck, Mich., a

corporation of Michigan Application January 24, 1944, Serial No. 519,492

3 Claims.

The invention relates to gear grinding machines of that type in which the gear is ground by a formed grinder wheel, the latter being trimmed to a cross sectional contour corresponding to the interdental contour of the nished work.

It is the object of the invention to adapt a grinding machine of this type to the grinding of gear teeth' which are non-rectilinear in an axial plane. For instance, in one form of gearing the engagement between conjugate gears when relieved from load is only in the central portion of the length of the gear teeth. Thus, at any deflection or deformation ofthe gear teeth due to load will be in the center and not at Vthe ends. With machines ofthe type above referred to the movement of the work relative to the grinder wheel is rectilinear and, consequently, the teeth are necessarily of the same contour and .radial dimension in all portions of the length thereof. However, by means of our improvement this condition is altered. 'Ihe invention, therefore, consists in the means for varying the distance between the axes of the work and grinder wheel during the relative axial movement thereof.

'Ihe invention further consists in the means for maintaining a xed relation between the axis of the grinder wheel and the trimming mechanism during the periodic retrimming operations.

Still further the invention consists in the peculiar construction and arrangement of parts as hereinafter set forth.

In the drawings:

Fig. l is a side elevation of a gear grinding machine to which our improvements are applied; and

Fig; 2 is an end elevation thereof.

In general construction our improved grinding machine comprises a base or bed A having guideways B thereon rfor a travelling work carrying table C. At one side of this table is a column D rising from the bed, said column having vertical guideways E for an adjustable cross head F on which the grinder wheel is mounted, the parts thus far described being similar to constructions heretofore used.

Instead of mounting the grinder wheel and its supporting arbor in xed bearings on the cross head F, these parts are mounted on an oscillatory frame G fulcrumed on said head. As shown, H is a shaft extending transversely through supporting bearings in the head F to extend on opposite sides of said head. I are antifriction ball or roller bearings mounted on the opposite ends of the shaft H and engaging seats in bifurcated arms G' of the frame G. J is the arbor for the grinder wheel which is journaled in bearings J to extend parallel to but spaced from the shaft H. At one end of this arbor is the driving motor J2 while atthe opposite end is mounted the grinder wheel J3 arranged above the table C. The gear to be ground, such as K,

lis mounted on centers on the table C to have its axis extend parallel to the guideways B and is also connected with a suitable indexing mechanism. However, as these parts are of conventional l construction illustration of the same is omitted in the drawings.

Mounted on the table C at one side thereof is a bar L on which is adjustably secured a cam member L'. M is a cam follower roll at the lower end of a rodM depending from. the frame G. The parts are so arranged that during the longitudinal movement of the tableV C through a distance equal to orgreater than the axial length of the gear teeth the cam follower roll M will ride over the' cam L' so as to raise and lower the oscillatory frame G and the grinder wheel J carried thereby. Thus, the path of the grinder wheel with respect to the work is curved in an axial plane and this curvature is determined by the shape of the cam L.

It is customary in grinding machines of the type to mount a trimming mechanism on the work holding table so that by moving this table beyond its work grinding position the trimming mechanism may be registered with the grinder wheel after which the trimming may be accomplished in the usual manner. Inasmuch, however, as the grinder wheel is moved vertically during oscillations of the frame G, it is necessary to hold this frame in a predetermined fixed position while it is in registration with the trim- ,ming mechanism. This is accomplished by a second cam member L2 mounted on the bar L and spaced from the cam L a distance equal to the distance between the grinding and trimming positions of the work table. One end of the cam L2 is curved or inclined to facilitate the mounting thereupon of the follower wheel M, while beyond this curved portion is a portion for holding the grinder wheel in its trimming position.

It is necessary to provide the machine with adjustments so as to accommodate the same to gear wheels of different diameters, and it is further necessary to make adjustments as the grinder wheel is periodically retrimmed and thus changed in radius. A screw N extending upward from the cross head F and cooperating with a nut (not shown) operated by a hand wheel N at the top o! the column D forms the means for vertically adjusting said cross head, this being the conventional means for moving the grinder wheel toward or away from the work in gear grinding machines. There is also a screw O mounted in the frameG and having a swivel connection with a rod M to extend upward in alignment therewith. This screw engages a nut mounted on their-ame G and at the upper .end of the screw is an operating crank handle On by which it may be revolved. A graduated sleeve O3 telescopically engaging a housing O* surrounding the screw indicates the. amount of rotative adjustment and a clamping screw O5 detachably connects this sleeve with the screw O. Thus, the sleeve may vbe moved to aero position and the amount of rotative adjustment of the screw thereafter accurately indicated.

-To limit the amount of of the frame G, the head F is provided with a forwardly extending arm F' having a button li*n thereon in alignment with a buttoni on said trame G. Thus, when the cam follower M dis engages from the cam L' the cooperating buttons Fl and F will limit the drop of the frame.A

In operation, the amount of axial curvature in the teeth of the gear being determined, a suitably proportioned cam L is mounted on the bar L. By means of an adjustable slide L3 on said bar andan adjusting screw L4 between the slide and cam, the latter may be accurately addownward 'oscillation Justed in position to correspond to the position of the work. The cam L -is also mounted and properly positionedv on the bar L. The grinder wheel is fashioned to the proper contour by moving the table C so as to anism P mounted on said table with the grinder wheel J3. In this position the ca'm Lz will hold the oscillatory frame G in a predetermined fixed position where the trimming is to be performed. Such position may. however, .be changed to compensate for wearV in the wheel by an adjustment of the screw O. After the grinder wheel is properly fashioned, the table is moved to its working position and is reciprocated through a length of movement corresponding to the length of the gear teeth. At the opposite ends of this movement the grinder wheel will be depressed but as it rides over the center of the cam L' it will be raised to its highest position. This will impart to the gear the desired longitudinal contour to the teeth.

register a trimming mechl What we claim as-our invention is:

l. In a grinding machine, the combination with a reciprocatory work carrying table, a mounting for a gear to be ground thereon and a formed grinder wheelof a laterally extending oscillatory frame above said table on which said grinder wheel is mounted, a bar mounted on said work table to extend parallel thereto, a cam on said bar, a cam follower depending from said oscillatory frame engaging said cam to raise and lower the grinder wheel during the axial movement of the work relative thereto, and asecond cam on said bar, the latter being adapted to position said oscillatory frame and grinder wheel for the trimming of the latter. f

2. In a grinding machine, the combination with a reciprocatory work carrying table, a mounting for a gear to be ground thereon and a formed grinder wheel of a stationary column, a head verticallyyadjustably mounted on said column,

an oscillatory frame pivotallymounted on said head and extending laterally therefrom, having a mounting for said grinder wheel intermediate its ends, a bar mounted on said work carrying table, a cam adjustably mounted on said bar, a cam follower depending from the free end of said oscillatory frame and engaging said cam to raise and lower the grinder wheel during the axial movement of the work relative thereto and cooperating members on said head and oscillatory frame for limiting the downward movement of the latter when said follower is disengaged from said cam.

3. In a grinding machine, the combination with a reciprocatory work carrying table, a mounting for a gear to be ground thereon and a formed grinder wheel of a laterally extending oscillatory -frame above said table on which said grinder wheel is mounted, a cam mounted on said work table, a pivotal support for said oscillatory frame -at one end thereof, a cam follower depending from the opposite end of said oscillatory frame engaging said cam to raise and lower the grinder 'wheel during the axial movement of the work relative thereto, a screw for adjusting said follower relative to said oscillatoryframe and extending upward above the latter, a handle for rotating said screw, and an indicator for the rotation of said screw determining the amount of adiustmentof said follower.

IVOR J. GRUENBERG. SAMUEL G. BRADY.