US1427818A - Antifriction-bearing mounting - Google Patents

Description

W. L. HUTCHINSON.

ANTIFRICTIONBEARING MOUNTING, /I'\PPLICATIONFILED JULYZO. 1921.

PatenwdSept. 1922,

Patented dept 5,

WALTER L. HUTCHINSON, OF HARTFORD, CONNECTICUT, ASSIGNOR 1'9 TEE $KAYEJF BALL BEARING QOIVEPAEY, A: CORPORATION OF GQNNECTICUT. I

ANTIFRICTIQN-BEARING IMOUNTIN Application rues zan 2e,

therein to the accompanying drawing.

invention relates to anti-friction This ' bearing mountings, and more particularly to the mounting of ball hearings in precision machinery especially that involving a rotary spindle. An illustrativeexample of an in stallation to which my improvement is peculiarly adapted is a spindle normally rotating at high speed and carrying a working tool which comes iutoengagement and leaves the work while rotating rapidly.

A basic principle of the invention is embodied in mechanism whereby the bearings, which if desired may be ball bearings, supporting the spindle adjacent the work performing portion, as for instance that carrying the grinding wheel or other rotary tool, are continuously under initial load in the direction of the working load, that is, the spindle is loaded or pressed in the direction of the pressure applied to it by its work, but materially in excess of such pressure to the end that there is no movement or tendency to movement of the spindle or the tool carried thereby upon its engagement with the work, and upon its leaving the work. An advantage of this is that the tool, as for instance, a grinding or polishing tool which has but a light engagement with the workpiece, may be presented to the work in such a manner that it does not in the initial application yield away from the work, which yielding causes chattering, and when it leaves the work does not move back toward the work,

which movement, when it occurs, againcauses chattering. and marrinp ot the finish produced by the tool. The tool carried by a spindle mounted according to my invention has a constant position relative to its sup-- port and does not have a normal running idle position different from the working position. In the drawings accompanying this application there is shown. by way of illustration, a practicable embodiment of the invention wherein the improved mounting applied.

1921. Serial H0, 488,108:

to the high speed spindla ot a grinding machine, such spindle being fshown niounted in a quill, in which drauungs Figure. l is a section taken axially of the spindle, and l v Fig. 2 is a cross section taken on a plane at about the line 2 -2 of Figure 1. The spindle 5, in the'present illustration, is intended to be rotated at high speed by means oii some suitable device, as for instance, a belt running upon pulley 6, and carries, as a working tool, a grinding wheel 7. The particular wheel illustrated is adapted for grinding the inner surface of a ring 8, such ring being in practice held in a suitable rotary chuck, the kind of grinding contemplated by this particular.installation being eficcted not only by a rotation of the grinding wheel, but also an oscillation there:

oil? imparted to the wheel from the casing or I quill 9 which is mounted on a suitable oscillatory base, not shown.

At the back or pulley end of the spindle there is sliownshitable anti-friction'support in the form of a bearing 10 fast to the spindle and mounted for axial movement in the quill, this being a common form of mounting needs no particular explanation.

it is quite necessary to rigidly support the front or wheel carrying end of the spindle,v

not only during its working period, but while it is approaching and coming into engagement with the work and while it is leaving the work and receding therefrom. hen bearings are mounted initially tight, this object is attained ion a short time, but only for a short time, and owing to the wearing down of the parts of the bearing, which in many instances is little more than a 1001-. islnng action. there 1s lntroduced a sutliclent 4 looseness to overcome the original accurate fit. This looseness necessitates tightening the bearings. This has been accomplished in various ways, generally in some manner which requires the demounting of the spindle and the disassemblage of the entire ball bearing construction. According to my invention, howeveigthe initial tightness and the maintenance of tightness may be had without removing any of the parts or opening the interior if the quill, it also takes care of bearing tightness as well as any slight looseness in fit of the outer races in their housing and effects of deflection of material.

Adjustment is capable of being effected While the spindle is running and the tool operating upon the workpiece.

To accomplish the adjustment and to afford a wide supporting base for the front end of the'spindle I mount upon it a plurality of bearings. In the illustration there are shown three two-row self-aligning bearings, A, B, and C, the inner races at, b, c, of which are locked against the shoulder 1 of the spindle by means of a suitable nut 12. The outer races, at b c of the iearings, are so mounted in a housing formed in the quill that the ring I) of the intermediate bearing of the three has its edges or sides free from the sides of the rings a. and c which are disposed laterally of it. ln closing up the casing the cap 13 is tightened against a shoulder 14 allowing a distance between the inside face 15, of the cap which engages the outer ring of the first hearing A, and the shoulder 16, for the inner bearing C, equal of the width of three normal outer races. The sides of the race Z) having been lapped off a small amount, it is free to move radially relatively to the rings upon its respective sides. The bearing housing portion of the quill is provided with a chamber 17 which is formed as a groove so that the hearing 13 may move radially, the side bearings A and C, of course, being held from such radial movement.

At the work engaging side of the spindle. a cradle 18 is mounted, which is in the form of a segmental shoe located in the chamber 17, and supporting the ring Z). A set screw 19 engages this cradle, and is located in posh tion for forcing the cradle, and the bearing resting therein, in a direction parallel with the working load of the grinding whee]. Preferably the cradle or shoe is relieved opposite the set screw as at 20. This adds a certain amount of elasticity to the device and moderates the rigidity and harshness which might, otherwise, he found destructive to the hearings in some installations.

Adjustment of the bearings to take up slack and tighten them in the working direetion is accomplished by screwing in the set screw 19 thereby moving the bearing supported by the cradle, and with it the spindle 5, in the direction which it tends to move owing to this working load. Preferably the load placed upon the said bearings by means of this adjustment is in excess of any load which will be placed upon the spindle by its work. This set screw preferably made quite small to safeguard the bearings agaifist unskillful adjustment, thereby presenting a construction the care of which need not necessarily be specially entrusted to highly skilled machine operators.

It is to'be understood that the example shown herein while embodying a preferred form of construction is illustrative of the inear/sis vention, and that changes in details may be made as occasion demands, within the scope of the claims, without departing from the spirit of the invention.

.1 claim as my invention 1 The combination with a spindle, of a mounting therefor comprising a housing and three anti-friction bearings, and means for applying pressure to the intermediate bearing.

2. he combination with a spindle, of a casing therefor, a pair of antiriction bearings housed in the casing and supporting the spindle, a bearingintermediate these hearings and mounted on the spindle, the outer portion of this bearing being circumferentially free of the housing, and pressure applying means engaging said intermediate bearing.

3. A hearing mounting comprising a spindle and a casing therefor, a plurality of antifriction bearings mounted upon the spindle and housed in the said casing, and means for applying radial pressure to one of the said bearings for applying initial tension tn the other bearings of the set in the direction of the working pressure to which the spindle is adapted to be subjected.

4:. A spindle adapted at one end for carrying a working tool, a housing in the form of a quill surrounding the spindle, three bearings provided with rolling element-s located within the quill and mounted upon the tool carrying end of the spindle, and means active upon the centrally located bearing for applying pressure to the spindle in the direction of the line of reaction from the tool engagement with its work,

5. The combination with a spindle adapted at one end to carry a working tool, of three anti-friction bearings provided with rolling elements mounted upon said spindle adjacent the tool carrying end, the inner races being locked together and the outer races being out of engagement one with the other, a casing surrounding said bearings and affording a housing having a fit with the outermost bearings and free the outer ring of the innermost bearing, and means for engaging the outer ring of the intermediate" bearing and applying a radial direction.

.6. The combination with a spindle, of three annular ball bearings located there on, a quill surrounding the spindle and propressure thereto in vided with a housing for the outer rings ofthe ball bearings, said housing being chambered out radially of the outer ring of the intern'iediate bearing, such rinp being free of the rings of the laterally disposed bean ings, a cradle located in the c lumber portion of the housing and engagin the outer ring of the intermediate bearing, and means for pressing the said cradle against such ring.

7. The combination with a spindle, of

eena-re three annular ball bearings located thereon,.

chambered out radially of the outer ring of the intermediate hearing, such ring being tree of the rings of the laterally disposed bearings, a cradle located in the chamber portion of the housing and engaging the'outer ring of the intermediate bearing, the cradle being a segment of less than half a circle and at its ends embracing the ring, it being relieved at the center portion and a set screw' carried by the quill and engaging the center portion of the cradle opposite the relief.

8. In a high speed spindle, the combination witha spindle having a Working end and a driven end, of a quill surrounding the spindle, and from the ends of Which the ends of the spindle project, ball bearing support for the spindle at the driven end, three ball bearings mounted at the work end, the inner rings of the said ball bearings being clamped together on the spindle, the quill at such end being formed with a housing adapted to engage in a suitable manner the outer rings of the laterally disposed bearings and being chambered out radially of the outer ring of the intermediate hearing, such ring being tree of the laterally disposed bearings, and a closure for the end of the quill having a suitable opening for the projecting work end of the spindle and adapted to engage the outer ring of the outermost lateral bearii'lg, there being provided stop shoulders "for limiting the closing movement of such closure whereby suflicient space is provided for permitting the aforementioned freedom between the sides of the outer rings, and means for moving the outer ring of the intermediate bearing radially. i

9. The combination With a spindle, of a casing therefor, an anti-friction bearing housed in the casing and supporting the spindle. a bearing adjacent thereto and mounted on the spindle, the outer portion of this latter bearing being circumferentially free of the housing, and pressure applying means engaging said latter bearing.

10. A spindle adapted at one end for carrying a working tool, a housing in the form of a 'quill surrounding the spindle, bearings provided with rolling elements located within the quill andinounted 11 391}, the tool carrying end of the spindle, and means active upon one of the bearings for applying pressure to the spindle in the direction of the line of reaction from the tool engagement with its work.

11. The combination with a spindle adapted at one end to carry a working tool, of anti-friction bearings provided with rolling elements mounted upon said spindle adjacent the tool carrying end, theinner races being locked together and the outer races being out of engagement one with the other. a casing surrounding said bearings and atfording ,a housing having a tit with the outer ring of one of the bearings and free of the outer ring otinnother of the said hearlugs, and means for engaging the outer ring of the latter bearing and applying pressure thereto in the direction of the working pressure to which the spindle is adapted to be subjected.

In testimony whereof. I have alfixed my signature hereto.

WALTER L. HUTCHINSON.

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