US3245731A

US3245731A - Ball way package

Info

Publication number: US3245731A
Application number: US275801A
Authority: US
Inventors: Carl F Erikson
Original assignee: Sundstrand Corp
Current assignee: Sundstrand Corp
Priority date: 1962-11-26
Filing date: 1963-04-23
Publication date: 1966-04-12
Anticipated expiration: 1983-04-12
Also published as: DE1425120B1; CH446823A; GB1046477A; FR1529509A; JPS504912B1

Description

April 12, 1966 c. F. ERIKSON 3,245,731

BALL WAY PACKAGE Filed April 23, 1963 4 Sheets-Sheet 1 Q) Q .....A U 50 11 INYENTOR.

April 12, 1966 C. F. ERIKSON BALL WAY PACKAGE Filed April 23, 1963 4 Sheets-Sheet 3 April 12, 1966 ERIKSON 3,245,731

BALL WAY PACKAGE I Filed April 23, 1963 4 Sheets-Sheet 4.

J15 QQAQQQQAQAQAQ 1 A C QQIQKQIQIQIQIQIQIQIQUQE United States Patent 3,245,731 BALL WAY PACKAGE Carl F. Erikson, Belvidere, I]l., assignor to Sundstrand Corporation, a corporation of Illinois Filed Apr. 23, 1963, Ser. No. 275,801 15 Claims. (Cl. 308-6) This application is a continuation-in-part of application Serial No. 240,065, filed November 26, 1962, now abandoned.

This invention relates to mechanism providing an improved mounting for movable parts and, more particularly to a ball way package.

An object of this invention is to provide a bearing unit avoiding side forces which result in deflections resulting in improper positioning of moving parts or which necessitates more massive constructions to minimize such deflections.

Another object of this invention is to provide a ball way package in which the ball bearings are free to move along any desired path within limits to avoid substantial side forces.

Still another object of the invention is to provide a ball way package in which ball bearings travel about a circuit including a load zone in which they contact a bearing surface of the package body and pass through a channel having opposite ends adjacent the ends of the bearing surface with means for holding the ball bearings in association with the body and causing a ball bearing to leave a channel end in centered relation to the channel, the channel being of a size greater than the ball-bearings, while permitting movement of the bearing along said bea'ring surface at an angle to a line between the centers of said channel ends.

A further object of the invention is to provide a ball way package as defined in the preceding paragraph in which there are a series of rows or circuits of ball bearings, each with a channel through which the ball bearingspass and with the means for guiding a ball bearing comprising, a plurality of wires, there being a wire at each side of a row of ball bearings, with the wires being spaced apart a distance less than the diameter of a ball bearing and spaced from the bearing surface less than the diameter of the ball bearing with the ends of the wires being mounted to the package body to permit lengthwise movement of the wires as they flex, said wires being positioned to receive a ball bearing in centered relation to the channel end as a bearing exits said channel.

A still further object of the invention is to provide a ball way package as defined in the previous paragraph with means for taking up clearance as the movably supported member moves relative to the way.

And another object of the invention is to provide a ball way package with means for preloading the package a given predetermined amount.

Further objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a fragmentary elevational view with parts in section showing the mounting of a machine tool component onto a guide way;

FIG. 2 is a vertical section through a ball way package taken generally along the line 22 in FIG. 3 andshowing a package similar to that shown in FIG. 1;

FIG. 3 is a vertical section taken generally along the line 33 in FIG. 2;

FIG. 4 is a fragmentary section taken generally along the line 4-4 in FIG. 3;

FIG. 5 is a fragmentary elevational view showing a ball way package having taken up means;

FIG. 6 is a sectional view taken substantially as shown along line 6--6 of FIG. 5;

ice

FIG. 7 is an end view of a Wedge member of the present invention;

FIG. 8 is a sectional view taken along line 88 of FIG. 7.

FIG. 9 is a central sectional view of a modified ball way package similar to that shown in FIG. 5; and

FIG. 10 is a plan view of the structure shown in FIG. 9.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention together with a modification thereof with the understanding that the present disclosure is to he considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated. The scope of the invention will be pointed out in the appended claims.

The ball way package disclosed herein is provided for supporting one part for substantially free motion relative to another part without imposing side forces. At the present time, machine tools are built and furnished with controls to obtain extremely accurate positions. These positions can only be obtained in a machine tool if the relatively movable parts do not have uncontrollable forces applied thereto.

As shown in FIG. 1, atable or slide indicated generally at 10 is movable relative to a pair of ways, with one of the ways being indicated generally at 11. The association between these parts is only shown in connection with one way 11; however, a similar mounting would be provided in conjunction with a second way.

The slide or table 10 is associated with the Way 11 by means of a plurality of ball way packages, three being shown in FIG. 1 indicated generally at 12, 13 and 14, with the package 12 supporting the weight of the movable part 10, the package 13 performing the side guiding of the movable part 10 and the ball way package 14 being of the gib type. The ball way packages are mounted with side clearance and each of the

packages

12 and 13 are engaged centrally along their length by blocks 15 and 16, respectively, to take up the forces exerted through the ball way package, with the contact area being purposely small with-respect to a load Zone of the ball way package subsequently to be described and centered on this zone so that the loads will be evenly distributed over all the ball bearings. The ball way packages are mounted against the blocks 15 and 16 in a manner to permit slight tilting of the ball way packages either transversely or longitudinally to allow for inaccuracies in parallelism between the surfaces of part 10 Where contacted by blocks 15 and 16 and the way surfaces.

Each of the ball way pack-

ages

12 and 13 are of basi cally the same construction and the package 12 will be described in detail and is shown in FIGS. 2, 3 and 4 as typical of both the

packages

12 and 13.

The ball way package 12 comprises an elongate bod 20 with a pair of

end caps

21 and 22 which are secured to opposite ends of the body by suitable means such as.

a flange screw 23. Each package body is provided with an enlarged portion, such as shown at 20a in package 12, which is positioned next to the adjacent slide or table surfaces to provide means for guiding the package whenit tilts longitudinally about its center support. One side 24 of the body 20 constitutes a bearing surface for ball bearings. There are four rows or circuits of ball bearings 25, 26, 27 and 28, which pass along the bearing surface 24 and complete the circuit through a series of channels formed within thebody 20. These channels are indicated at 29, 3t 31 and 32. The channels each have curved sections, such as sections 32a and 32b for the channel 32 which terminate in ends 32c and 32d adjacent opposite ends of the bearing surface 24. Each row or ircuit of ball bearings includes a sufiicient number to ompletely fill the associated channel and to form a row f bearings engageable with the bearing surface 24.

A primary feature of the invention is the control of 1e ball bearings to permit relatively free travel of the earings from one channel opening to the other. It ill be apparent that the ball Way package must operate 1 either direction of travel of the machine slide 16, a that balls can travel either into or from the channel pening 32c. Referring to FIG. 4, a center line running etween the centers of channel openings 32c and 32d is hown in broken line extending between points M and I. The channels 29-32 are of a size greater than the ball eari-ngs as is apparent in FIGS. 2, 3, and 4 and, thus, the hannels cannot, of themselves, assure that a ball will e at either points M or N on either exiting or enter- 1g a channel opening.

Means are provided for assuring this central location f a ball bearing. This means also permits travel of the caring along an angled path relative to the line M-N, s the bearing travels through the load zone defined by he length of the bearing surface 24. Assuming a ball Iearing 28 exits the channel through the opening 32d, vs shown in FIG. 4, the means to be described will have he center of the ball along the line M-N. As the ball rrogresses to the channel opening 320, the ballcan folo-w the center line or can follow diverging lines with he extremes of divergence being shownby broken lines xtending between the point N and the points A and B. Donversely, a ball travelling in the opposite direction and liverge from point M to either point C or D.

This means comprises flexible members which function retain the ball bearings as part of the package and also 0 obtain the central positioning of a ball hearing as it :xits the channel while permitting subsequent travel along LII angled path. As shown in the drawings, the members [re a series of wires 40, 41, 42, 43 and 44 of a generally riangular cross section. The members may be formed lifferently; however, triangular wires provide greater vidth for holding ball bearings and provide a greater :ross sectional area resisting deflection for opposing drop )nt of ball bearings.

There are a pair of wires associated with each row )r circuit of ball bearings and the relationship is such vo permit use of a single wire between adjacent rows )f bearings. In every instance, the Wires define a pair For each row or circuit of ball bearings. Each pair of vires are spaced apart a distance less than the diameter )f a ball and spaced from the bearing surface 24 less ban the diameter of the ball to hold the hearings in as- ;ociation with the package and, as the wires flex, they nay move away from the bearing surface 24 since they 116 spaced from the surface of the way 1 1. The wires are each mounted for lengthwise movement as they are flexed by having the ends of each wires, such as ends 45 and 46 of the wire 43, loosely fitted in recesses 47 and 18, respectively, of the

end caps

21 and 22. Thus, the wires may flex as permitted by the loose mounting of the wire ends with a suflicient length of the wires being :lisposed with-in the recesses so that the wire ends cannot move entirely out of the recesses.

Again referring to FIG. 4, it will be seen that the wires 43 and 44 function to have the ball bearing 28 centrally located of the channel opening 32d as the ball bearing exits the channel. The wires 43 and 44 may then flex as a bearing tends to follow an angled path to permit the bearing to follow such path. If a ball bearing has done so, it can still freely move into the channel 320 because of the over-sizing thereof. The same action can occur if the ball way package is travelling in the opposite direction.

As will be seen in FIG. 2, the channels 29-32 are grouped and staggered in elevation to provide proper wall thickness between channels.

The ball way package 14, of the gib type, is of the same construction as described in connection with

packages

12 and 13; however, as seen in FIG. 1, only a single row of ball bearings 50 is utilized. However, the construction for the single row is the same as for any specific row of bearings shown for package 12.

With the foregoing construction, angular misalignment does not result in deflection forces which are of a value to be troublesome as compared to roller-type way packages in which rollers are restrained to move along a straight line and which require an accuracy of mounting which is substantially impossible to obtain.

Refer-ring now to FIGS. 5 and 6, means are shown in association with guide way package 13 for providing zero clearance between the package, and way 11. This means is indicated generally by reference numeral 60, and is in the form of a spring loaded wedge which functions to take up any clearance which may result as slide or table 10 moves relative to the ways. Take up means 60 includes a first wedge member 61 abutting package 13' and mounted thereon by suitable means, such as by pins 62 and 63. Wedge 61 includes a surface 64 which is inclined with respect to the surface .65 that engages package 13. A threaded bore 66 is provided in wedge 61, and is positioned in parallel-ism with surface 65.

Take up means 60 further includes a second wedge member 67 having a pair of spaced apartarms 68 and 69, a central pontion with an inclined surface 70 corresponding to the inclination of surface 64 and a surface 70a parallel to surface 65. The end-s 71 and 7 2 of

arms

68 and 69 are substantially parallel, and are provided with threaded

holes

73 and 74. An end .plate 75 abuts against ends 71 and 72, and is provided with a pair of clearance holes which are aligned with

holes

73 and 74, and which receive therethrough bolts 76 and 77 which are threaded into

holes

73 and 74 to secure end plate 75 to wedge 67.

End plate 75 is also provided with a central hole 78 that is aligned with bore 66 in wedge 61. A bolt 79 passes through .hole 78, and include-s an enlarged head 80 and a threaded end portion 81 threadably received in bore 66. A washer 82is disposed under head 80 and abuts against end plate 75; A spring 83 surrounds bolt 79 and abuts against end plate 75' and wedge 61.

It will be readily understood that by threading bolt 79 into bore 66, wedge surface 7021' will beforced inwardly with respect to package '13. This reduces the thickness of the assembly and enables it to he slipped into position against the ball package. Bolt 79 is then loosened until washer 82 is free and wedge surface 70a engages the adjacent surface of slide or table 10. Slide or table 1(i-is then moved back and forth and spring 83 will move wedge 67 outwardly with respect to package 13'to take up any clearance between package 13'j and way 11, and apply a predetermined amount of compressive preload to package 13'. Bolt 79 is then tightened until washer 82 is tight, and then the bolt is loosened a predetermined amount to provide take up=means for a desired maximum clearance between the ball package and the way which occurs during normal machine: operation.

Referring now to FIG. 9 and FIG. 10, a modified form of the ball way package is indicated in its entirety by reference numeral 90. Package includes an elongated body 91 having apertured

projections

92 and 93 at each end thereof. One side 94 of the body 91 constitutes a bearing surface for the ball bearings, one'now being shown at 95. Suitable channels, such as that shown at 96, are provided for each rowof bails which may be positioned at different elevations, as is shown in FIG. 1 and FIG.2.' Projections 92; and 93 are provided with corresponding grooves 97a and 971) which are adapted to receive balls 95, it being understood that a pair of grooves are provided for each row of balls. Apertured end caps 98- 101 are positioned against the body projections, with a set of opposed arcuate grooves 102a and 10% provided Q-unitary assembly.

in

caps

98 and 100, respectively, and a set of opposed arcua te grooves 103a and 103b provided in caps 99 and lolyrespectively. It will be readily apparent that channel 96, grooves 97a and 97b, grooves 102a and 10215 and 103a and 103b, and bearing surface 94 form a continuous path through which balls 95 travel. Flexible members, not shown, identical to those shown at 40-44 in 'FIG. lFIG. 4, are provided to retain a set of balls in its proper path, and to guide the balls into the arcuate open-ings',"such as those shown at 103a and 10317.

Bolts 104-107 impale the apertures in end caps 98- "101 and

projections

92 and 93 to retain the package as a i It will be appreciated that the package embodiment just described, obviates the necessity of providing lengthy tie rods, such as those shown at 23 in FIG. 1-FIG. 4.

' Take up means, similar to that shown in FIG. 5-F IG. 8, are also associated with package 90. Body 91 includes a pair of spaced

sides

108 and 109 on opposite 'sides of an inclined central surface 110 which defines a first wedge. A second wedge 111 is slidably mounted on surface 110 and includes an inclined face 112 correspending in inclination to surface 110, and a surface 113 parallel to bearing surface 94. Wedge 111 includes a threaded hole 114 that is parallel with surface 112, and which threadably receives the threaded end 115 of a bolt 116 that pasess through a suitable inclined aperture in end cap 100. The enlarged head 117 of bolt 116 is "seated in' a recess 118 provided in the face of end cap 100. Aspring--119 surrounds bolt 116 and engages an Iundercut inclined surface 120 on end cap 110 and wedge "111 to urge surface 113 away from bearing surface 94.

I claim:

1. A ball way package comprising, a body, a bearing surface at one side of the body, said body having a channel with ends adjacent the ends of said surface, a plurality of ball bearings with some positioned in said chan- 'nela'nd some against said surface, said channel ends being of a size greater than the ball bearings, and yieldable means for causing a ball bearing to be in generally centered relation to the channel as the ball bearing leaves the channel while permitting movement of the bearing along said surface in a straight line which is at an angle to a line between the centers of said channel ends because of said yieldability.

2. A ball way package as defined in claim 1 in which said means comprises a pair of flexible wires extending between the channel ends with their ends loosely mounted in said body, said wires being spaced apart a distance less than the diameter of a ball and located at a distance from said surface less than the diameter of a ball whereby one of the wires may flex in a direction away from said surface as a ball moves at said angle.

3. A ball ways package comprising, an elongate body, a bearing surface at one side of said body encompassing a load zone, a plurality of generally side-by-side channels in said body each having curved sections terminating in ends located adjacent opposite ends of and beyond said bearing surface, a row of ball bearings associated with each of said channels and including a sulficient number to substantially fill each channel and extend along said bearing surface, each of said channels being of a size greater than a ball bearing, and means for retaining the rows of ball hearings in association with said bearing surface comprising, a plurality of generally parallel flexible members with there being a member between rows of ball bearings and one outside of each of the outermost rows, said members being spaced apart a distance less than the diameter of a ball bearing and spaced from the bearing surface less than the diameter of a ball bearing, and recesses in said body at a distance beyond said bearing surface said recesses being located to position the members to engage a ball bearing leaving a channel end and guide the bearing for exit centrally of the channel width and into the load zone while permitting movement of a ball bearing along said bearing surface at an angle to a line between the centers of opposite channel ends by flexing of a member with the members receiving a ball bearing after the bearing has left the load zone.

4. A bearing for use between a fixed member and a movable member comprising, a body adapted to be secured to one of said members and having a bearing surface adapted to be disposed adjacent the other member, said body having a channel with opposite ends adjacent opposite ends of said surface, a plurality of bearing elements positioned in said channel and some engaging said surface, a first wedge secured to the body, said wedge having a surface inclined with respect to said bearing surface and a threaded bore, a second wedge movable along said inclined surface and having a face substantially parallel to said bearing surface, and yieldable means for moving said second wedge along said inclined surface including a bolt threadably received in said bore and a spring surrounding said bolt and biased against said second wedge.

5. A bearing as defined in claim 4 wherein said second wedge includes a pair of spaced apart arms, and an end plate spanning the ends of said arms and secured thereto, said spring acting between said first wedge and said end plate to create said bias. g

6. A ball package between a movable member and a fixed way member comprising, a body carried by one are a plurality of ball bearing circuits positioned to carry substantially parallel loads each including a channel with one of said axes being parallel to said circuits to distribute the load among the circuits.

8. A ball way package for use with a machine tool to have a machine tool element movable relative to a Way with minimum friction and side loading said package comprising, a body, a bearing surface at one side of the body, said body having a channel with ends adjacent the ends of said surface, a plurality of ball bearings with some positioned in said channel and some against said surface, said channel ends being of a sizegreater than the ball bearings, and yieldable means for causing a ball bearing to be in generally centered relation to the channel as the ball bearing leaves the channel while permitting movement of the bearing along said surface in a straight line which is at an angle to a line between the centers of said channel ends because of said yieldability.

9. A package as defined in claim 8 in which said body constitutes a beam having a neutral axis and there are a plurality of rows of ball bearings with each row having an individual one of said channels, said channels being positioned adjacent said neutral axis.

10. A ball way package comprising, a body, an exposed bearing surface at one side of the body, said body having a channel with opposite ends thereof adjacent opposite ends of said surface, a plurality of ball bearings positioned one after the other to form a row extending along said surface and through said channel, and flexible members extending along both sides of the bearings which en gage the bearing surface, said flexible members being mounted on said body at a distance beyond the ends of said bearing surface to provide a length thereof beyond the ends of the bearing surface which is flexible, said members retaining the ball bearings in the package and being yieldable along a length thereof greater than the length of the bearing surface to permit movement of the earings along a straight path which may be at an angle 'etween ends of the channel while recentering a bearing teyond an end of said bearing surface.

11. A package as defined in claim 10 in which said nembers are wires of triangular cross section.

12. A ball way package comprising, a body having a rearing surface, said body having a channel with opposite inds thereof adjacent opposite ends of said surface with aid ends defining a ball exit Zone and a ball entry zone elative to the bearing surface functionally interchangelble dependent upon the direction of ball travel, a pluality of ball bearings positioned some in said channel and ome engaging said surface, with the balls traveling beween end entry and exit zones being substantially free of :onstraint against lateral movement, laterally spaced [part guide means at the Zones effective alternatively deendent on the direction of ball bearing travel to deliver he ball bearings from the entry Zone at an intermediate )osition between the guide means intermediate the exreme lateral positions of ball travel, and means mounting laid guide means at a distance beyond the ends of said rearing surface to have said guide means engage a ball herebetween in said exit zone beyond the bearing surface For centering of the ball without side loading on the package.

13. Apackage as defined in claim 12, in which said nounting means is provided by a member separate from said body, and means for holding said member assembled said body.

14. A ball Way package as defined in claim 12 in which said body is composed of a central section and apertured,

nembers at opposite ends thereof, said channel having ion-linear part thereof formed in said members, and means passing through the apertures of saidrnembers and adjacent parts of said central section for fastening said members and central section.

15. A ball way package comprising, an elongate body having opposed ends with apertured projections, bearing surface at one side of said body, a plurality of channels in said body, apertured end caps secured-to the opposed ends of said body and abutted against said projections with the end cap apertures aligned with the projection apertures, connective rnernbers extending through said aligned apertures to secure said endcaps to said body, channels in said end caps communicating with said body channels and having curved sections terminating in ends located adjacent opposite ends of said bearing surface,.a row of ball bearings including a sufficient number to fill the channels and extend along said bearing surface, said channels being of a size greater than a ball bearing, and means for retaining the row of ball bearings associated with said bearing surface and for guiding thereof comprising, a pair of generally parallel guide members, said guide members being spaced apart a distance less than the diameter of a ball and space-d fromthe bearing surface less than the diameter, of a ball and being mounted beyond tl16:611dS of said bearing surface, said guide members being positioned to engage a ball bearing leaving an end cap channel end and guide. the bearing for exit centrally of the end cap channel width while permitting movement of a ball bearing along said surface at an angle to .a line between the centers of opposite end cap channel ends and receipt of an oil-center ball. bearing entering a channel.

References Cited by the: Examiner UNITED STATES PATENTS 835,324 11/1906 Rice 308-22 1,881,675 10/1932 Klausmeyer et a1 308- 6 3,086,824 4/1963 Barley 30 86 3,115,373 12/1963 Alexander 308-42 FOREIGN PATENTS 836,261 6/ 1960 Great Britain.

DON A, WAITE, Primary Examiner. FRANK SUSKO, ROBERT C. RIORDON, Examiners.

Claims

1. A BALL WAY PACKAGE COMPRISING, A BODY, A BEARING SURFACE AT ONE SIDE OF THE BODY, SAID BODY HAVING A CHANNEL WITH ENDS ADJACENT THE ENDS OF SAID SURFACE, A PLURALITY OF BALL BEARINGS WITH SOME POSITIONED IN SAID CHANNEL AND SOME AGAINST SAID SURFACE, SAID CHANNEL ENDS BEING OF A SIZE GREATER THAN THE BALL BEARINGS, AND YIELDABLE MEANS FOR CAUSING A BALL BEARING TO BE IN GENERALLY CENTERED RELATION TO THE CHANNEL AS THE BALL BEARING LEAVES THE CHANNEL WHILE PERMITTING MOVEMENT OF THE BEARING ALONG SAID SURFACE IN A STRAIGHT LINE WHICH IS AT AN ANGLE TO A LINE BETWEEN THE CENTERS OF SAID CHANNELS END BECAUSE OF SAID YIELDABILITY.