Linear ball bearing.

The invention relates to a linear ball bearing for guiding an object on a cylindrical shaft, comprising

a bearing block<ul><li>with a mind molded, substantially planar contact surface for contacting the object,</li><li>with fastening means for connection with the object and</li><li>with a plurality of ball loops, each of which in radial planes - are arranged and each having a radially inner, carrying ball row, a radially outer, returning ball row and - - to the axis of the cylindrical shaft relative close to the axial ends of the bearing block - Umlenkbogenkugelreihen for connecting a respective radially inner, carrying ball row and a radially outer, returning ball row, said radially inner rows of balls distributed radially outward to an inner cylindrical surface axially extending wings are supported and run between spaced apart in the peripheral direction of the guide surfaces,</li><li>the radially outer rows of balls in return channels extend,</li><li>the deflection curve-ball rows are guided by a convex, axially outward Ringwulstfläche and concave, axially inward semicircle gutters,</li><li>the guide surfaces and the semi-arc grooves are arranged at a cage assembly which has connecting them, the half-arc grooves having Hakenflansche over the length of the wings extending guiding ribs and at the axial ends of the guide ribs,</li><li>said Hakenflansche each having an axially inward Hakenendfläche abut an axially outward channel mouth area of ​​recycling channels,</li><li>said Hakenflansche ever an outer circumferential surface for having on an inner circumferential surface and</li><li>wherein the cage assembly is divided into a the guide webs intersecting perpendicular to the axis parting plane into two half-cages.</li></ul>

Such a linear ball bearing is known from prior public use by the applicant and by a brochure "STAR Linear Set with Radial Linear Bushing".

In the known embodiment, the ball loops in a ball produced separately from the bearing block are housed bush. This known embodiment has therefore proved very successful, because this ball sleeve finished in accommodating the ball loops in a separate from the bearing block linear bushing in large series and can subsequently assemble with various forms of bearing blocks. About disadvantages of this known solution, nothing has been published to date.

It has now been recognized by the applicant that in the known solution but may occur certain problems:<ul><li>By installing a linear bushing disposed therein _Kugelschleifen in a bearing block add up precision error on the bearing block and the ball bush, so that compliance with the regularly required narrow tolerances is difficult. The spatial superposition of linear bushing and bearing block leads to large dimensions with a correspondingly high weight. but Lowloader are often undesirable in view of limited installation space and large weight results in high accelerations of the object to increased mass forces.</li></ul>

Based on this finding, the task was set to produce a linear ball bearing of the type described in undiminished load rating and undiminished rigidity with increased precision while reducing weight and dimensions.

To achieve this object, the invention proposes that the wings, the return ducts, the Innenumfanqsflächen and the axially outward qerichteten Kanalmündunqsflächen are anqeformt to the material of Laqerbocks.

It has been found that the manufacture of the wings, the return ducts, the Ringwulstfläche who Innenum catch surfaces and axially outward channel mouth areas can be done on the material of the bearing block with high efficiency, so that the BEEN feared detriment of disestablish the mass production of has been standard ball bushings at least compensated for the use in bearing blocks of different shape.

The linear ball bearing of the invention are, for example, intended to guide carriage in the machine tool.

The linear ball bearing according to the invention may be configured to comprise the cylindrical shaft part, _d, _H, is designed with an opening (ring opening). In this case, the respective shaft can be supported by the ring opening pervasive restraints within the guide track. But it is also possible in the round form linear ball bearing according to the invention so as to include the respective cylindrical shaft completely and this can be supported only outside of the respective guide track.

It may be provided for pressing the bearing balls against the cylindrical shaft pressing means. In the arrangement of the contact surface on a side remote from the ring opening side of the bearing block can be an inset to the bearing surface substantially paraller slot in a to the contact surface is substantially vertical, axially parallel side face of the bearing block with respect to a Andrückmöglichkeit, which is preferably up to approximately to the pitch circle the Rückfilhnmgskanäle is introduced; Hereby it can be received in a lying on one side of the slit part of the bearing block to a slot the plane substantially perpendicular Getindebohrung which receives a versoannbaren against located on the other side of the plane of the slot part of the bearing block threaded bolts. Generally speaking, for the slot depth, that they must be large enough on the one hand, to achieve a sensible attitude, on the other hand there are still much Pestwandstärke remains that sufficient strength is present. It has been shown that with this embodiment of the radials^pieleinstellung least affects the rigidity of the linear ball bearings against bending moments perpendicular to the bearing surface axis.

The wings may be formed either by a cylindrical inner surface of the bearing block or by raceway grooves. In the case of track grooves the osculation is increased; thereby a substantial increase in the_TRAG number and a further improvement of the rigidity attained.

The precision can be further increased by the fact that the guide bar portions of the half-cages are mortised in the separation plane with each other, said tenon joint may be effected by external pins that are inserted in recesses at the mutually facing ends of the guide webs or by complementary tenon and pin receptacles, which at the mutually facing ends of the guide webs are integrally formed.

The bearing block may be provided with a grease duct system, which starts from a well in the cultivation of the bearing block free access to the object surface of the bearing block to any time bring lubricant can. Such a lubrication duct system can be produced in a simple manner in that a is in a substantially axially normal plane drilled to the bearing surface substantially parallel primary channel and for connection to said primary channel, a secondary channel is drilled from the abutment face forth, which in the region of the contact surface by a plug is completed. This secondary channel can then open into the cylinder inner surface of the bearing block between two adjacent ball loops. In this way, two rows of balls are supplied directly with lubricant. The remaining rows of balls can be supplied by lubricant which flows from the directly supplied ball rows forth across the shaft circumference. Hakenflanschen to the can to seal the lubricant against leakage to the outside and be attached to prevent entry of dirt and foreign bodies and the sealing elements, although such sealing elements can be attached to the Hakenflanschen respectively in the region of an axially outer and radially inner annular edge. For the case of a trained only for partial encirclement of the cylindrical shaft linear ball bearing, it is also possible

provide at the associated ring-opening edges of the cage assembly sealing strips for abutment on the shaft.

The cage assembly may be secured by securing rings in the axial direction, which are engaged in molded onto the bearing block grooves. In view of achieving easy build construction linear ball bearing with a low weight, it is possible, that is without impairing the rigidity and load capacity of the distance between the cylinder inner surface of the clamping area 25% to 50%, preferably 30% to 50% of the diameter of the associated shaft. The distance of axis-parallel, to the mounting surface substantially perpendicular side surfaces of the bearing block from the cylindrical inner surface may be 65% to 120%, preferably 75% to 120% of the diameter of the associated shaft.

The accompanying figures illustrate the invention with reference to embodiments. It represents:<ul><li>Figure 1 is an end view partly in section along line II of Figure 2 through an inventive linear ball bearings..;</li><li>Fig. 2 is a plan view of the linear ball bearing of Fig. 1;</li><li>Fig. 3 is a section along line III-III of Fig. 1; </li><li>Fig. 4 is a section corresponding to that of Figure 3 but without balls.</li><li>Fig. 5 is a section along line VV of Fig. 1;</li><li>Fig. 6 is an enlarged partial section on VI of FIG. 1;</li><li>Fig. 7 is a corresponding partial section of Figure 6 in a modified embodiment. and</li><li>Fig. 8 a of FIG. 6 corresponding partial section with another modified embodiment.</li></ul>

In Fig. 1, a bearing block is indicated at 10. This bearing block has a clamping surface 12 with which the bearing block is placed on the object to each leading to the plant. For accurate lateral positioning of the bearing block 10 on each object a stop edge is 14. To secure the bearing block 10 on the respective object are provided threaded bores 16th However, it is also possible to introduce bolt 18 from below in the through holes, which are then screwed together with threaded holes at the respective object.

A bore 20 (Fig. 2) allows for pinning.

The bearing block 10 has a bore with a cylindrical inner surface 22nd The hole is open in the contact surface 12 opposed by a ring opening 24 area. For guiding the bearing block 10 on a recorded from the bore the cylindrical shaft a plurality of ball loops 26 are provided which are based in each case in a radial plane to the axis A R of the associated not shown shaft. The ball loops 26 comprise a radially inner row of balls 26a, a radially outer returning ball row 26b and 26c Umlenkbogenkugelreihen.

The radially inner row of balls runs 26a of FIG. 6 to a supporting surface 22a which is a part of the cylinder inner surface 22. Laterally, the balls of the ball bearing radially inner row are seen as 26a in FIG. 1 and 6, guided by guide ridges 28a where the guide surfaces are formed 28aa. The guiding ribs are part of a cage assembly 28, which is divided in the axis-normal dividing plane T into two half cages 281 and 28II.

The radially outer returning ball rows 26b are guided in return channels 30th The Umlenkbogenkugelreihen 26c are guided by an axially directed outwardly convex Ringwulstfläche 32 from the material of the bearing block 10 and through a respective separate, axially inwardly directed concave semicircle groove 28c. The half-arc grooves 28c are formed on an annular hook flange 28b of cage assembly 28th The Hakenfla nsch 28b can be seen in particular in Figs. 4 and 5. The hook flange 28b is located with an outer peripheral surface 28d at an inner peripheral surface 34 of the bearing block 10. The hook flange 28b has a Hakenendfläche 28e, which abuts against a duct opening surface 36 of the bearing block 10th The guide ribs 28a abut the barrel inner surface 22 or spaced therefrom by a small gap. The cage assembly 28 is fixed in the bearing block in the axial direction by two retaining rings 38, which are engaged in grooves 40 of the bearing block 10th In the circumferential direction, the cage assembly 28, as seen in Fig. 1, as determined by the edge lips 44 which abut against the boundary surfaces of the ring opening 24. In addition, a longitudinal rib 46 is provided in each case, which engages in a groove of the bearing block 10th

At the cage assembly 28 sealing elements 48 are mounted on the axial ends thereof, which are intended to rest on the cylindrical-shaft. At the cage assembly 28 24 sealing strips 42 are also mounted in the ring opening. The sealing elements 48 and the sealing strips 42 are glued, inserted in grooves or fixed by ultrasonic welding. Its purpose is to prevent lubricant from escaping, and to prevent the entry of dirt to the rows of balls. The sealing elements 48 and the sealing strips 42 are made of plastic or elastomeric material. The sealing elements 48 are inserted in annular grooves 50 of the respective half cage 28I or 28II.

The facing ends of the guide ribs 28a of the two half cages 28I and 28II are secured by pins 52 against each other and held in alignment. The pins 52 may be replaced by integrally formed complementary projections and chambers.

The linear ball bearing has, as shown in FIG. 1 can be seen, a relubrication with a primary lubrication channel 54 which extends in an axis-normal surface substantially parallel to the bearing surface 12 and intersects with a secondary passage 56 which is drilled from the abutment face 12 and to the cylinder inner surface 22 between two successive ball loops 26 ie between the respective radially inner bearing ball rows of these _Kugelschleifen ends. The secondary bore 56 is closed at its outer end by a plug 58th The water introduced through the lubricant channels 54, 58 of the side surface 60 ago lubricant reaches the inner bearing rows of balls 26a of the two adjacent ball loops 26 and distributed to all other ball grinding, in which it flows over the circumferential surface of the cylindricity Welle.

To adjust the bearing clearance, a slot 62 is cut coming from the side surface 60 in the bearing block 10, which reaches up almost to the pitch of the feedback channels 30 and is substantially parallel to the contact surface 12th In the part 10a of the bearing block 10 has a threaded bore 64 is inserted, which receives a clamping bolt 66th The clamping bolt 66 presses with its upper end in a pan 68 of the located on the other side of the slot 62 portion 10b of the bearing block 10. By UP-screws of the clamping bolt 66, the portion 10a of the bearing block in a clockwise direction about the inner end of slot 62 left standing web material are pivoted elastically, whereby the radial clearance can be adjusted. It may also be a bias can be adjusted, whereby an enlarged rigidity is achieved. It is also possible to provide two adjustment slots; the second adjustment slot could be arranged symmetrically with respect to the first adjustment slot on a line passing through the axis A vertical plane of symmetry in FIG. 1.

It is also conceivable for the ring opening 24 1 to move relative to the representation of FIG. 90 °.

To increase the load capacity by improving the osculation 8 ball rolling grooves 122 are provided in FIG.. Although the ball tracks require a higher production cost, but result in a considerable increase in load capacity and to further improve the stiffness.

Referring to FIG. 7, the ball grooves 222a arranged on ribs 270 of the bearing block.

The enveloping circle tolerance (radial clearance) and the height tolerance can be reduced: was opposite the bearing design known presume, has the following advantages. While the known linear ball bearings, the enveloping circle tolerance is determined by three variables (core diameter of the ball bushing, sleeve outer diameter of the ball bushing, inner diameter of the bore in the bearing block) according to the invention only one size of influence, namely the diameter of the cylindrical inner surface 22. The height tolerance, ie the dimension between the abutment surface 12 and the axis of the cylinder inner surface 22 only depends on a size that is the base thickness, that is, the distance between the abutment surface 12 and the cylinder inner surface 22 from. According to the prior art, this height tolerance was dependent on three variables, namely the core diameter and the sleeve outer Esser the linear bushing and the bottom thickness of the bearing block.

The weight reduction compared to the initially discussed known embodiments is 60 to 70%. The dimensions were lower than this known embodiment as follows: reduction in length (measured in the axial direction) by 35 to 42%; Width reduction (perpendicular to the surface 60 measured) 16 to 29%; Height reduction measured perpendicular to the contact surface 12 27 to 33%. In a typical installation of four bearing units results as for a shaft diameter of 80 mm, a weight saving of about 186 kg. The four storage units weigh even about 118 kg (up to 304 kg with the known Anordnungl. It is of course assumed undiminished load rating and the same rigidity.

The weight reduction is particularly in modern machines are of great interest, which operate with ever increasing speeds and thus larger accelerations, because the mass forces are significantly reduced by this weight savings, so that the drives can be performed weaker and more economical.