US3247621A

US3247621A - Machine assembly

Info

Publication number: US3247621A
Application number: US328410A
Authority: US
Inventors: Aller Willis Fay
Original assignee: Sheffield Corp
Current assignee: SHEFFIELD MACHINE TOOL COMPANY A CORP OF OH; Sheffield Corp
Priority date: 1963-12-05
Filing date: 1963-12-05
Publication date: 1966-04-26
Anticipated expiration: 1983-04-26
Also published as: GB1077018A

Description

April 26, 1966 w. F. ALLER 3,247,621

MACHINE ASSEMBLY Filed Dec. 5, 1963 2 Sheets-Sheet 1 INVENTOR. WILLIS FAY ALLER L FIG.2 BY

4 ms ATTORNEY April 26, 1966 I w. F. 'ALLER 3,247,621

MACHINE ASSEMBLY Filed Dec. 5, 1963 2 Sheets-Sheet 2 FIG.3 T

- INVENTOR.

2 WILLIS FAY ALLER BY W 3 it ms ATTORNEY United states Patent 3,247,621 MACHINE ASSEMBLY Willis Fay Aller, Dayton, Ohio, assiguor to The Shetfield Corporation, Dayton, Ohio, a corporation oi Delaware Filed Dec. 5, 1963, Ser. No. 328,410 9 Claims. (Cl. 51-1345) This invention relates to bearing supports for rotatable members and more particularly to such a support for use in machine tools such as grinding machines wherein varying grinding conditions on workpieces of different alloys and materials, conditions of changing load as occur during infeed in a single grinding operation, and internal stresses introduced by high and varying operating temperatures, all create extremely severe load and operating conditions.

In such applications it is important that rigidity be maintained for accuracy in grinding, that bearing pre-load be applied and maintained under varying operating conditions which would otherwise tend to create high and destructive internal temperature and stress conditions, and that the grinding wheel and its support, while being rigidly mounted, be readily accessible and easily removed, replaced or adjusted.

It is accordingly an object of this invention to provide a rotatable support for severe load conditions, particular- .ly applicable to wheelheads of grinding machines, which support has unique features of construction and adjustment for rigidity, maintenance of desired bearing operating conditions, and reduction of internal operating stresses and temperatures.

It is a further object to provide such a bearing support wherein, through a unique relationship of adjustment structure and spaced bearings between a fixed central spindle and an outer rotatable load or grinding wheel carrying housing, by a single simple adjustment bearing preload is obtained in both bearing assemblies and maintained under varying load conditions in an arrangement which is extremely simple, involving a minimum number of parts, all of simple configuration and economical manufacture.

It is a further object of this invention to provide such a support wherein the support and grinding wheel are uniquely housed and mounted through an outer door fitted within the housing for rigidity and receiving the outer spindle end therein for spindle support, said door being mounted for initial rectilinear movement along the spindle axis for clearance and then swinging to make accessible the end faces of the wheel and all support components, the inner spindle end being held in a supponting housing recess by detachable means accessible from the exterior of the housing.

Other objects and advantages of the invention will be apparent from the following description, the appended claims, and the accompanying drawings, in which:

FIG. ,1 is an exemplary application of the invention in a machine tool,

FIG. 2 is a cross section on the line 22 of FIG. 4,

FIG. 3 is an enlargement of one-half of the section of FIG. 2,

FIG. 4 is a view on the line 44 of FIG. 2 showing the door assembly used to support one end of the nonrotating spindle, and

FIG. 5 is a fragmentary sectional view illustrating a further embodiment of the present invention wherein spring means are used to maintain the preloading of the bearing assemblies.

In FIG. 1 the invention is shown in an exemplary embodiment as applied to the wheelhead of a grinder 10. Grinder has a base 11 which includes a longitudinal r 3,247,621 Patented Apr. 26, 1966 way 12 which supports a headstock 13 and a tailstock 14 for movement to predetermined positions therealong. Headstock 13 and tailstock 14 include centers 15 for carrying workpiece 16 thereon. A wheelhead assembly 17 movable on base 11 toward and away from the workpiece location carries a grinding wheel 20.

As illustrated in FIG. 2, grinding wheel 20 is mounted through an adapter 19 on an annular load receiving housing 21.- A central non-rotating supporting spindle 22 is fixed mounted on wheelhead 17 through grinding wheel enclosure structure including casting 23. The inner end of spindle 22 is inserted into a closely receiving recess 24 in casting 23 and is fixed therein by releasable fastening means illustrated as a plurality of bolts 25 which are accessible from the outside of the grinding wheel enclosure 23. Spindle 22 is also supported at its opposite end by a door 26 mounted for swinging movements on casting 23;

As shown particularly in FIGS. 3 and 4, door 26 has a supporting recess 27 therein which is of part conical configuration for receiving and supporting the correspondingly tapered outer end of spindle 22. Door 26 is closely fitted within enclosure casting 23 at its major peripheral edge for radial support thereby as indicated at 30 and during operation is bolted to casting 23 by a plurality of bolts 31. Door 26 is provided with compound hinge means 28 ,(hinged at its points of connections with casting 23, door 26, and intermediate these connections) which carry it for initial rectilinear movement along the axis of the spindle to enable it to clear both fitting engagement with enclosure casting 23- and the cooperating conical portion of spindle 22, and then enable the door to be swung away in a conventional manner for complete and ready access of the grinding wheel assembly without requiring disassembly of the machine.

Annular housing 21 is mounted on spindle 22 through combination radial and axial

thrust bearing assemblies

32 and 33 which, as shown in FIGS. 2 and 3, are relatively spaced therealong and is driven through belt 50 from an electric motor forming a part of wheelhead assembly 17. Assembly 32 includes inner ring 34 and outer ring 35 with rotatable antifriction elements such as tapered roller bearings 36 therebetween. Similarly assembly 33 includes inner and outer rings 37 and 40 respectively and roller bearings 41 therebetween. As shown,

assemblies

32 and 33 are mounted adjacent opposite ends of spindle 22. As forces are applied to grinding wheel 20 they are transferred through housing 21 and bearing

assemblies

32 and 33 to spindle 22.

In using such combination axial and radial thrust bearing assemblies each assembly takes axial thrust directed in one direction along spindle 22. In the illustrated application the cones of revolution of

antifriction rollers

36 and 41 face oppositely and toward the corresponding ends of spindle 22 for opposed thrust efiectiveness.v Thus assemblies 32 and 33 respectively transfer axial thrust between housing 21 and spindle 22 directed toward the corresponding or adjacent spindle ends.-

The inner surfaces of inner rings 34 and 37 fit closely on spindle 22. The outer surfaces of outer rings 35 and 40 fit closely within housing 21. First axial restraining means is provided between spindle 22 and inner rings 34 and 37 restricting these rings only against movement on spindle22 in the respective directions of axial thrust transfer through the respective bearing assemblies. Second restraining means between outer rings 35 and 40 restrict these rings against movement relative to housing 21 only in directions opposite to the directions of axial thrust effectiveness of the respective assemblies.

The second restraining means in the illustrated embodiment includes shoulders 44 and 45 on housing 21 acting against rings 35 and 40 respectively.

The first restraining means in the illustrated embodiment includes a shoulder 42 on spindle 22 engaging ring 34 and resiliently yieldin' means, illustrated in FIGS. 2 and 3, as a ring or washer 43 of resilient material held in position against ring 37. Ring 43 can be, for example, made of neoprene. The first restrainingmeans also includes adjustable means such as lock nut 38 adjustably threaded on spindle 22 and acting through spacer 39 on washer 43. Lock nut 38 is adjustably threaded along spindle 22 to achieve any desired and controlled initial preloading of the bearing assemblies through resilient washer 43. Axial movement of locknut 33 on spindle 22 will, through spacer 39, compress or preload bearing assembly 33, and the resultant axial force on housing 21 to the right as viewed in FIG. 3 will similarly compress or preload assembly 32. Thus washer 43 is operative on both

bearing assemblies

32 and 33 and through its resilient yielding maintains the preloading effective throughout varying load conditions caused, for example, by operating on different materials and by stresses introduced by differential temperatures and relative expansion of components during the grinding cycle.

Controlled loading of

bearing assemblies

32 and 33 may also be achieved using other resiliently yielding means applied through either the first or second restraining means. For example, a plurality of compression springs 51- of the type illustrated in FIG. 5 may be installed about spindle 22 in the same relative position as washer 43 to achieve the desired preloading.

As previously mentioned and as illustrated in FIG. 3, adaptor 19 is provided for mounting grinding wheel 20 on annular housing 21. Adaptor 19 is readily installed by bolts 47 as illustrated. During machine setup, a grinding wheel and adaptor may be removed in a rapid and efiicient manner and a new one installed on housing 21 by simply opening hinged door 26 exposing bolts 47 and the end of the spindle. Bolts 47 are then removed and grinding wheel 26 and adaptor 19 are simultaneously removed from the machine as an assembly through the use of a suitable fixture fastened to the assembly.

Thus it is seen that a rotatable support and wheelhead assembly is provided wherein a load carrying member rotates in a frictionless and cool manner by controlling and maintaining through a simple adjustment and a simple mechanical arrangement the relative loading of bearing assemblies which support the member. Provision is included for ready access to and ready removal and replacement of operating components.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein Without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A rotatable support for severe load conditions comprising,

a central non-rotating supporting spindle,

an annular load receiving housing,

combination radial and axial thrust bearing assemblies relatively spaced along said spindle, each of said assemblies including inner and outer rings respectively cooperating with said spindle and said housing and rotatable antifriction elements therebetween, said assemblies having opposed thrust effectiveness and respectively transferring axial thrust in opposite directions between said housing and said spindle, said bearing assemblies being mounted on said spindle to receive a load from said load receiving housing directed generally transverse and between said assemblies, said bearing assemblies providing the sole support for said housing while holding said housing radially spaced away from said s indle, restraining means cooperating between said spindle and each of the inner rings of said bearing assemblies restricting said inner rings against movement with respect to said spindle in the respective directions of axial thrust transfer through the respective bearing assemblies,

restraining means cooperating between said housing and each of the outer rings of said bearing assemblies restricting said outer rings against movement with respect to said housing in respective directions opposite to the direction of axial thrust effectiveness of the respective bearing assembly,

said restraining means including adjustable means for obtaining effective preloading between the components of at least one of said bearing assemblies,

and resiliently yielding means in said restraining means operative on both bearing assemblies for maintaining said preloading effective throughout varying operating and load conditions.

2, A rotatable support for severe load conditions comprising,

a central non'rotating supporting spindle,

an annular load receiving housing,

combination radial and axial thrust bearing assemblies relatively spaced. along said spindle, each of said assemblies including inner and outer rings respectively cooperating with said spindle and said housing and rotatable antifriction elements therebetween, said assemblies having opposed thrust effectiveness and respectively transferring axial thrust between said housing and said spindle directed toward the corresponding end of said spindle, said bearing assemblies being mounted on said spindle to receive a load from said load receiving housing directed generally transverse and between said assemblies, said bearing assemblies providing the sole support for said housing while holding said housing radially spaced away from said spindle,

restraining means cooperating between said spindle and each of the inner rings of said bearing assemblies restricting said inner rings against movement with respect to said spindle in the respective directions of axial thrust transfer through the respective bearing assemblies,

restraining means cooperating between said housing and each of said outer rings of said bearing assemblies restricting said outer rings against relative movement toward one another,

at least one of said restraining means including adjustable means for obtaining effective preloading between the components of said bearing assemblies,

3 A rotatable support for severe load conditions comprising,

a central non-rotating supporting spindle,

an annular load receiving housing,

combination radial and axial thrust roller bearing assemblies relatively spaced along said spindle, each of said assemblies including inner and outer rings respectively cooperating with said spindle and said housing and tapered roller antifriction elements therebetween inclined with respect to the axis of said spindle, the cones of revolution of said antifriction elements for the respective bearing assemblies facing oppositely and in the direction of the corresponding ends ofsaid spindle for opposed thrust effectiveness and respectively transferring axial thrust between said housing and said spindle directed toward the corresponding spindle ends, said bearing assemblies being mounted on said spindle to receive a load from said load receiving housing directed generally transverse and between said assemblies, said bearing assemblies providing the sole support for said housing while holding said housing radially spaced away from said spindle,

first restraining means cooperating between said spindle and each of the inner rings of said bearing assemblies restricting the respective inner rings against movement with respect to said spindle in the respec tive directions of axial thrust transfer through the respective bearing assemblies,

and second restraining means cooperating between said housing and each of said outer rings of said hearing assemblies restricting said outer rings against relative movement toward one another,

said first restraining means including adjustable means on said spindle adjustable along said spindle and axially against one of said inner rings for applying compressive force to the corresponding hearing assembly and through said housing to the other of said bearing assemblies for obtaining effective preloading between the components of, both said bearing.

assemblies, through a single adjustment, said adjustable means including resiliently yielding means operative through the corresponding inner ring on both bearing assemblies for maintaining said preloading effective throughout varying operating and load conditions.

4. A wheelhead assembly for grinding machines comprising,

a carrier adapted for mounting on the base of such a machine for movement therealong in a grinding operation, 1

a spindle,

means supporting and fixedly mounting said spindle against rotation on said carrier,

an annular load receiving housing,

a grinding wheel carried by said housing,

combination radial and axial thrust roller bearing assemblies relatively spaced along said spindle, each of said assemblies including inner and outer rings respectively cooperating with said spindle and said housing and tapered roller .antifriction elements therebetween inclined with respect to the axis of said spindle, the cones of revolution of said antifriction elements for the respective bearing assemblies facing oppositely and in the direction of the corresponding ends of said spindle for opposed thrust effectiveness and respectively transferring axial thrust between said housing and said spindle directed toward the corresponding spindle ends, said bearing assemblies being mounted on said spindle to receive a load from said load receiving housing directed generally transverse and between said assemblies, said bearing assemblies providing the sole support for said housing while holding said housing radially spaced away from said spindle,

first restraining means cooperating between said spindle and each of the inner rings of said bearing assemblies restricting the respective inner rings against movement 'with respect to said spindle in the respective directions of axial thrust transfer through the respective bearing assemblies, 7

second restraining means cooperating between said housing and each of said outer rings of said bearing assemblies restricting said outer rings against relative movement toward one another,

said first restraining means including adjustable means threaded on said spindle adjustable therealong axially toward the outer end face of the adjacent one of said inner rings for directly applying compressive force to the corresponding bearing assembly and throughsaid housing to the other of said bearing assemblies for obtaining effective preloading between the components of both said bearing assemblies, through a single adjustment, said adjustable means including resiliently yielding means oper ative through said adjacent inner ring on both said bearing assemblies for maintaining said preloading effective throughout varying operating and load conditions,

and drive means on said carrier operatively connected to said housing for rotation of said housing and said grinding wheel in forming operations.

-5. A wheelhead assembly as set forth in claim 4 in which said resiliently yielding means includes an annular ring of resilient material carried concentrically on said spindle with said adjacent inner ring;

6. A wheelhead assembly as set forth in claim 4 in which said resiliently yielding means includes spring means about said spindle and effective in compression axially therealong.

7. Awheelhead assembly for grinding machines comprising,

a carrier adapted for mounting on the base of such a machine for movement therealong in a grinding operation,

a spindle,

rmeans supporting and fixedly mounting said spindle against rotation on said carrier,

an annular load receiving housing,

a grinding wheel carried by said housing,

combination radial and axial thrust roller bearing assemblies relatively spaced along said spindle, each of said assemblies including inner and outer rings respectively cooperating with said spindle and said housing and tapered roller antifriction elements therebetw'een inclined 'with respect to the axis of said spindle, the cones of revolution of said antifriction elements for the respective bearing assemblies facing oppositely and in the direction of the cor- I responding ends of said spindle for opposed thrust eifectiveness and respectively transferring axial thrust between said housing and saidspindle directed toward the corresponding spindle ends,

first restraining means cooperating between said spindle and each of the inner rings of said bearing assemblies restricting the respective inner rings against movement with respect to said spindle in the respective directions'of axial thrust transfer through the respective bearing assemblies,

' second restraining means cooperating between said housing and each of said outer rings of said bearing assemblies restricting said outer rings against relative movement toward one another,

said first restraining means including adjustable means threaded on said spindle adjustable therealong axially toward the outer end face of the adjacent one of said inner rings for directly applying compressive force to the corresponding bearing assembly and through said housing to the other of said bearing assemblies for obtaining efiective preloading between the components of both said bearing assemblies, through a single adjustment, said adjustable means including resiliently yielding means operative through said adjacent inner ring on both said bearing assemblies for maintaining said preloading elfective throughout varying operating and load conditions,

drive means on said carrier operatively connected to said housing for rotation of said housing and said grinding wheel in forming operations,

said means supporting said spindle providing an enclosure for said grinding wheel,

said supporting means comprising a supporting recess for receiving the inner end of said spindle and re-- leasable fastening means accessible from the outside of said enclosure for mounting the inner spindle end therein,

a door in said enclosure at the outer spindle end fitted within said enclosure at its major peripheral edge for radial support, said door having a supporting recess. therein of part conical configuration, the' outer end of said spindle being correspondingly conformed for fitting reception therein for supporting the outer spindle end,

and compound hinge means carrying said door for initial rectilinear movement along the axis of said spindle to clear said door of fitting engagement at its periphery with said enclosure and of said supporting recess relative to said outer spindle end and swinging movement thereafter to expose the end faces of said grinding wheel, housing, and spindle.

8. A wheelhead assembly for grinding machines comprising,

said supporting means comprising a supporting recess for receiving the inner end of said spindle and releasable fastening means accessible from the outside of said enclosure for mounting the inner spindle end therein,

a door in said enclosure at the outer spindle end fitted within said enclosure at its major peripheral edge for radial support, said door having a supporting recess therein of part tapered configuration, the outer end of said spindle being correspondingly conformed for fitting reception therein for supporting the outer spindle end,

9. A wheelhead assembly for grinding machines comprising,

'means supporting and fixedly mounting said spindle against rotation on said carrier,

an annular load receiving housing,

a grinding wheel carried by said housing,

radial and axial thrust roller bearing assemblies cooperating between said spindle and said housing for transferring axial and radial thrust loads between said housing and said spindle,

restraining means including adjustable means cooperating between said spindle and said housing for directly applying forces parallel to said spindle axis to at least one of said bearing assemblies and through said housing to the other of said bearing assemblies for obtaining effective preloading of said bearing assemblies through a single adjustment, said adjustable means including resilient yielding means operative on both said bearing assemblies for maintaining said preloading effective throughout varying operating and load conditions,

References Cited by the Examiner UNITED STATES PATENTS 2,182,012 12/1939 Bunnell 308-35 2,457,537 12/1948 Douglass 308-187 2,735,240 2/1956 Fries et al. 51166 LESTER M. SWINGLE, Primary Examiner.

Claims

4. A WHEELHEAD ASSEMBLY FOR GRINDING MACHINES COMPRISING, A CARRIER ADAPTED FOR MOUNTING ON THE BASE OF SUCH A MACHINE FOR MOVEMENT THEREALONG IN A GRINDING OPERATION, A SPINDLE, MEANS SUPPORTING AND FIXEDLY MOUNTED SAID SPINDLE AGAINST ROTATION ON SAID CARRIER, AN ANNULAR LOAD RECEIVING HOUSING, A GRINDING WHEEL CARRIED BY SAID HOUSING, COMBINATION RADIAL AND AXIAL THRUST ROLLER BEARING ASSEMBLIES RELATIVELY SPACED ALONG SAID SPINDLE, EACH OF SAID ASSEMBLIES INCLUDING INNER AND OUTER RINGS RESPECTIVELY COOPERATING WITH SAID SPINDLE AND SAID HOUSING AND TAPERED ROLLER ANTIFRICTION ELEMENTS THEREBETWEEN INCLINED WITH RESPECT TO THE AXIS OF SAID SPINDLE, THE CONES OF REVOLUTION OF SAID ANTIFRICTION ELEMENTS FOR THE RESPECTIVE BEARING ASSEMBLIES FACING OPPOSITELY AND IN THE DIRECTION OF THE CORRESPONDING ENDS OF SAID SPINDLE FOR OPPOSED THRUST EFFECTIVENESS AND RESPECTIVELY TRANSFERRING AXIAL THRUST BETWEEN SAID HOUSING AND SAID SPINDLE DIRECTED TOWARD THE CORRESPONDING SPINDLE ENDS, SAID BEARING ASEMBLIES BEING MOUNTED ON SAID SPINDLE TO RECEIVE A LOAD FROM SAID LOAD RECEIVING HOUSING DIRECTED GENERALLY TRANSVERSE AND BETWEEN SAID ASSEMBLIES, SAID BEARING ASSEMBLIES PROVIDING THE SOLE SUPPORT FOR SAID HOUSING WHILE HOLDING SAID HOUSING RADIALLY SPACED AWAY FROM SAID SPINDLE, FIRST RESTRAINING MEAN COOPERATING BETWEEN SAID SPINDLE AND EACH OF THE INNER RINGS OF SAID BEARING ASSEMBLIES RESTRICTING THE RESPECTIVE INNER RINGS AGAINST MOVEMENT WITH RESPECT TO SAID SPINDLE IN THE RESPECTIVE DIRECTIONS OF AXIAL THRUST TRANSFER THROUGH THE RESPECTIVE BEARING ASSEMBLIES, SECOND RESTRAINING MEANS COOPERATING BETWEEN SAID HOUSING AND EACH OF SAID OUTER RINGS OF SAID BEARING ASSEMBLIES RESTRICTING SAID OUTER RINGS AGAINST RELATIVE MOVEMENT TOWARD ONE ANOTHER, SAID FIRST RESTRAINING MEANS INCLUDING ADJUSTABLE MEANS THREADED ON SAID SPINDLE ADJUSTABLE THEREALONG AXIALLY TOWARD THE OUTER END FACE OF THE ADJACENT ONE OF SAID INNER RINGS FOR DIRECTLY APPLYING COMPRESSIVE FORCE TO THE CORRESPONDING BEARING ASSEMBLY AND THROUGH SAID HOUSING TO THE OTHER OF SAID BEARING ASSEMBLIES FOR OBTAINING EFFECTIVE PRELOADING BETWEEN THE COMPONENTS OF BOTH SAID BEARING ASSEMBLIES, THROUGH A SINGLE ADJUSTMENT, SAID AJUSTABLE MEANS INCLUDING RESILIENTLY YIELDING MEANS OPERATIVE THROUGH SAID ADJACENT INNER RING ON BOTH SAID BEARING ASSEMBLIES FOR MAINTAINING SAID PRELOADING EFFECTIVE THROUGHOUT VARYING OPERATING AND LOAD CONDITIONS, AND DRIVE MEANS ON SAID CARRIER OPERATIVELY CONNECTED TO SAID HOUSING FOR ROTATION OF SAID HOUSING AND SAID GRINDING WHEEL IN FORMING OPERATIONS.