DE202018105401U1 - Ball roller, in particular polymer ball roller, and applications for this - Google Patents

Abstract

Ball roller (1) with a housing (11, 12) and a running ball (2), in particular a polymer ball running in the direction of a bearing axis (A) through a housing opening (14), wherein a matched to the running ball, concave bearing surface (13) is provided in the housing, on which the running ball (2) by means of a number of intermediate bearing balls (4), with a diameter which is significantly smaller than the running ball diameter, is mounted, characterized in that the concave bearing surface (13) at least one the bearing ball diameter adapted recess (15), and the bearing balls (4) in a corresponding recess (15) einliegen to keep them in a predetermined relative position to the running ball (4).

Description

The invention relates generally to a ball roller with a housing and a ball running, viewed in the direction of a bearing axis, protruding from the housing through a housing opening with respect to the running ball smaller diameter, wherein in the housing adapted to the running ball, concave bearing surface is provided on which the running ball by means of a number of smaller balls (hereinafter: bearing balls) is freely rotatably mounted. The bearing balls are used for rolling bearing and are located between the ball and the bearing surface in the housing and have a diameter which is typically significantly smaller than the diameter of the running ball.

Such generic ball rolls are particularly used in transport or storage devices e.g. used on ball roller tables, transport tables, support devices or storage tables. Often, a plurality of ball rolls are arranged in a horizontal plane, so that on the upwardly protruding parts of the balls, e.g. a workpiece can be placed and moved in any direction within the plane.

Generic ball rolls can be varied, e.g. also for the storage of moving parts, such as on a piece of furniture, on workbenches or assembly workstations, etc., or as wheels or wheels to wheels used to carry mobile objects.

DE102012100575A1 describes a generic ball roller. A generic ball roller unit for the conveyor technology is still in DE19622903C2 described, there with resilient support of the running ball.

In the known designs, a plurality of bearing balls for rolling bearing is arranged disorderly and freely movable between the running ball and the bearing surface.

It has been found that the possible applications, in particular with regard to the installation position, are limited by the typical design. In addition, it is only possible to achieve good, even, smooth running as well as possible.

An object of the invention is thus to propose an improved design of a ball roller, which is equally applicable in any mounting position and / or has a smoother, quieter running behavior.

In a generic ball roller according to the preamble of claim 1, the object is achieved in that the concave bearing surface has at least one adapted to the bearing ball diameter recess, and that the bearing balls einliegen in an associated or corresponding recess to the bearing balls rotatable therein and in a predetermined relative position to be held on or to the outer surface of the running ball, in particular to keep the bearing balls against an axial position change with respect to the bearing axis along the surface of the running ball.

The bearing balls can thereby change their position relative to the running ball only within the space defined by the recess. It may be provided for a part of the bearing balls for all bearing balls a common contiguous depression or a plurality of distributed recesses. Each recess must be adapted to the bearing ball diameter at least insofar that the bearing balls on the recess and thus the adjacent bearing surface at least slightly or predominantly protrude, on the other hand, the bearing balls are movable only within the corresponding recess.

Already from this simple optimization of the housing interior results in a significant advantage, namely that the ball roller in any mounting position, also, for example. can be used with horizontally and obliquely or vertically downwardly directed bearing axis, because the bearing balls always maintain a load-bearing or load-bearing position relative to the running ball thanks to this holding recess (s). In addition, a comparatively smooth and quiet run can be achieved. In other words, the intended possible position of the bearing balls is limited to the portion of the recess or wells, so that the bearing balls regardless of the installation position and other operating conditions their position only in the predetermined by the selected arrangement of the recess (s) space area, in particular in relation on the running ball, can change.

As a running ball, a polymer running ball, in particular made of a tribo-polymer, is particularly preferably used-which enables lubrication-free and therefore low-maintenance or -free operation during the long service life. The bearing balls are preferably held with the technically desired small movement in the respective recess.

In a preferred, relatively easy to produce embodiment is provided as a coaxial recess arranged coaxially to the bearing axis in the concave bearing surface whose radius is adapted in cross section to the bearing ball diameter, so that the bearing balls einliegen or held with little play in it. In particular, exactly one around the bearing axis completely circumferential annular groove as a recess be provided. This can accommodate all bearing balls, ie simplify the assembly and / or specify a circular track for the bearing balls, ie allow uniform in all directions support the balls. Thus, the depression can be a kind of circumferential groove in which the smaller bearing balls run, and these change their spatial position only on this circular path.

Alternatively, it is also conceivable to provide a number of recesses spatially distributed around the running ball in the concave bearing surface, e.g. three separate annular groove sections or sectors along a surface circle of the running ball. A distributed arrangement of the depressions is conceivable up to a 1: 1 assignment corresponding to the number of bearing balls, i. each own, separate recess for each ball roll.

For a good load bearing or distribution each annular groove is preferably - based on the nominal position of the running ball center - in an angular range of the polar angle (Poldistanzwinkels) or elevation angle (in polar coordinates with the ball center as the origin and the bearing axis as a pole axis) to the bearing axis of about 25 ° to 55 °, esp. From 30 ° to 45 ° arranged.

The depth or the cross-sectional dimensioning (in the section containing the bearing axis) of the or each recess may be selected so that an inset bearing ball projects with a predominant volume fraction over the bearing surface to avoid unnecessary friction and / or that each ball bearing vertically standing bearing axis remains held in the recess, which simplifies installation.

In a particularly preferred for the life and a lubrication-free operation embodiment, a running ball made of plastic is used. The running ball can be made of polyoxymethylene (POM).

The smaller bearing balls are preferably made of metal, in particular stainless steel. In applications, e.g. however, with strong magnetic fields (e.g., in an MRI), preferably, glass bearing balls are used.

Particularly high durability and carrying capacity are achieved with the material combination POM stainless steel, in particular a POM bearing ball with stainless steel bearing balls. The stainless steel bearing balls are paired with a bearing surface on the first housing part, which is made of a lubricant-free tribopolymer, to minimize wear there and to increase the service life ..

Preferably, the housing has a first housing part made of a tribopolymer, which has the bearing surface with the recess or the depressions, and a housing part having the second part, preferably made of plastic.

The bearing surface is preferably made approximately semispherical or semi-spherical, which is e.g. can be implemented inexpensively by injection molding. The same applies to the second housing part, e.g. a ring-shaped retaining ring, which preferably has a part-spherical retaining surface for the running ball, which surrounds the housing opening. In particular, the housing preferably consists only of the two housing parts, which can be advantageously produced as molded parts in plastic-if appropriate both of a tribopolymer-in particular by injection molding. This will u.a. reduced the manufacturing and assembly costs.

In a mechanically favorable design of the smaller bearing ball diameter is in the range of about 10% to 35% of the running ball diameter, in particular in the range of about 15% to 25%. Regardless, for typical applications, the ball may have a barrel diameter in the range of about 5mm to 50mm. In the direction of the bearing axis, the main component of the load is removed or derived. The bearing axis is mechanically determined by the housing design, and corresponds geometrically usually the line through the predetermined nominal position of the running ball center in the housing and the center of the housing opening, according to the main direction of the force exerted by the load to be supported.

The proposed optimization of the ball roller is suitable for a wide variety of known applications and also for hitherto unobjectionable application areas, e.g. in an installed position, in which the running ball is directed obliquely or vertically downwards.

A common application of the ball roller according to the invention relates to conveyor systems, in particular in a ball roller table, a roller conveyor of a conveyor line, a transport table or the like.

The proposed ball-roll may also be used in a storage-technical system, e.g. a rack storage system, e.g. be used as a roller on a storage box or a pallet.

Furthermore, the ball roller for storage of a movable component, in particular a piece of furniture, such as drawers, pull-outs and the like., Or be used by moving parts of a sports or fitness equipment. However, the use of the invention is not limited to those mentioned Application examples limited, but basically advantageous.

• 1: einen vertikalen Längsschnitt durch den Gesamtaufbau einer Laufrolle gemäß einem ersten Ausführungsbeispiel;
• 2A-2B: einen Längsschnitt bzw. eine Draufsicht einer Variante eines Gehäuseteils für die Laufrolle nach 1; und
• 3: eine perspektivische Ansicht des Gehäuseteils gemäß 2A-2B.

Further details, features and advantages of the invention will become apparent - without limiting the generality of the above teaching - from the following detailed description of a preferred embodiment with reference to the accompanying drawings. Hereby show:

• 1 a vertical longitudinal section through the overall structure of a roller according to a first embodiment;
• 2A-2B a longitudinal section and a plan view of a variant of a housing part for the roller after 1 ; and
• 3 a perspective view of the housing part according to 2A-2B ,

In 1 is generally with reference numerals 1 a preferred embodiment of the ball roller referred. The main components of the ball roller 1 are the load-bearing running ball 2 , a two-part housing, namely a first lower housing part 11 and an upper lid-like housing part 12 , as well as a number of bearing balls 4 ,

The first housing part 11 forms a bearing shell with a here approximately hemispherical bearing surface 13 into which the running ball 2 is inserted. The running ball 2 is on the bearing balls 4 supported or stored according to the principle of rolling bearing. These are the bearing balls 4 in the first housing part 11 rotatable with respect to the bearing surface 13 stored. The bearing balls 4 transfer the load from the running ball 2 on the storage area 13 , ie on the serving as a storage rack housing part 11 , The two housing parts 11 . 12 are rotationally symmetrical to the bearing axis A Run and hold the ball center M the running ball 2 on this bearing axis A ,

The diameter of the running ball 2 D ₂ = 2 × R ₂ is considerably larger than the diameter D ₄ = 2 × R ₄ the bearing balls 4 for example, by a factor in the range of about 3-6. The radius R ₂ the running ball 2 may be in the range of about 2-50mm, preferably 2-25mm, or larger. The radius R ₁₃ the dome-shaped storage area 13 is greater than the radius by a predetermined amount R ₂ the running ball 2 , The difference is smaller than the diameter D ₄ the bearing balls 4 as will be seen below.

As 1 and 2A Best illustrate is in the concave storage area 13 as a recess for partially receiving and guiding the bearing balls 4 an annular groove 15 intended. The ring groove 15 is toroidal, coaxial with the bearing axis A and arranged completely circumferential.

The ring groove 15 is in cross section at the radius R ₄ the bearing balls 4 customized. This is the radius R ₁₅ the ring groove 15 , so dimensioned that the bearing balls 4 with little play in the ring groove 15 can roll freely.

In the example shown here is exactly a completely circumferential annular groove 15 rotationally symmetrical about the bearing axis 5 is provided. Other arrangements, for example, several distributed Ringnutabschnitte or distributed wells for individual bearing balls 4 are conceivable.

The ring groove 15 is preferably in the region of the lower half of the hemispherical bearing surface 13 arranged here approximately at a polar angle ( θ ) of about 40 ° with respect to the bearing axis A with the ball center M as origin. The depth of the ring groove 15 measured from the adjacent storage area 13 is chosen so that a predominant volume fraction of the bearing balls 4 over the storage area 13 protrudes to the friction surface of the bearing balls 4 at the storage area 13 to minimize. On the other hand, the bearing balls should 4 for simplified installation with vertically aligned bearing axis A in the recess or annular groove 15 stay stable.

The ring groove 15 forms a kind of track groove in which the smaller bearing balls 4 run free and between the running ball 2 and the first housing part 11 from a tribopolymer in a desired relative position with respect to the running balls 2 are held. The bearing balls 4 are in 1 so to speak in orbit with polar angle ( θ ) around the axis A guided.

Thanks to the recess or ring groove 15 can the bearing balls 4 regardless of the applied load, they are not displaced from their desired nominal position (under normal use and when installed). The bearing balls 4 can in particular also in an inclined or vertically downward installation position of the ball roller 1 do not slip down or into a no longer load-bearing position. Furthermore, due to the arrangement and geometry of the recess 15 limited in a predetermined manner position of the bearing balls 4 a comparatively smooth and smooth running of the running ball 2 achieved. In particular, in comparison to the conventional arrangement with disordered bearing balls also allows a smaller number of bearing balls 4 be used, since no filling of the space between running ball 2 and the storage area 13 is required.

The running ball 2 is preferably made of a commercially available plastic, for example a polyoxymethylene (POM). The bearing balls, however, are preferably made of metal, more preferably made of stainless steel. As bearing balls, for example, commercial Rolling bearing balls are used. As a running ball 2 can also be used commercially available bearing balls made of plastic.

2A-2B show further details of the housing design. The first housing part 11 is made of a lubricant-free tribolymer (tribologically optimized polymer plastic with tribological additives, such as, for example, solid lubricants), preferably by injection molding. The housing part 11 forms next to the storage area 13 with the preformed recess or annular groove 15 furthermore a flange-like projecting assembly collar 17 frontally on the cylindrical outer surface and one in this assembly collar 17 seat provided 19 for pressing or attaching the second housing part 12 in a suitable receptacle or bore. The second housing part 12 has as housing opening 14 a part-spherical retention surface, which is symmetrical to the bearing axis A is arranged and after attaching the second housing part 12 in the seat 19 the running ball 2 Centric on the bearing axis with little movement play A holds. As with the material pairing between running ball 2 and bearing balls 4 may also be in terms of the tribopolymer of the housing parts 11 . 12 in relation to the running ball 2 be selected from commercially available plastic tribologically favorable material pairing.

With the design according to the invention can in combination with the material pairing between running ball 2 and bearing balls 4 a total lubrication-free operation and a very long life, including due to very low abrasion, can be achieved. Particularly preferred are the Gehäusteteile 11 . 12 from the material "Xirodur B180" from the company igus GmbH from D-55147 Cologne.

The proposed design is, inter alia, thanks to compliance with a proper position of the bearing balls 4 Finally, a higher load bearing allows. Depending on the dimensions, loads of several 100 N can be achieved, even with small sizes, eg with a running ball 2 With R ₂ ≤ 25mm.

LIST OF REFERENCE NUMBERS

1-3

1

ball roller

2

run ball

4

Bearing balls (supporting balls)

11

first housing part

12

second housing part

13

storage area

14

housing opening

15

Recess / groove

17

mounting collar

19

Seat (for housing cover)

A

bearing axle

θ

Polar angle (to the bearing axis)

R ₂

Radius of the running ball

R ₄

Radius of the bearing balls

R ₁₃

Radius of the storage area

R ₁₅

Radius of the annular groove

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012100575 A1 [0004]
• DE 19622903 C2 [0004]

Claims (13)

Ball roller (1) with a housing (11, 12) and a running ball (2), in particular a polymer ball running in the direction of a bearing axis (A) through a housing opening (14), wherein a matched to the running ball, concave bearing surface (13) is provided in the housing, on which the running ball (2) by means of a number of intermediate bearing balls (4), with a diameter which is significantly smaller than the running ball diameter, is mounted, characterized in that the concave bearing surface (13) at least one the bearing ball diameter adapted recess (15), and the bearing balls (4) in a corresponding recess (15) einliegen to keep them in a predetermined relative position to the running ball (4). Ball roll after Claim 1 , characterized in that as a recess coaxial with the bearing axis (A) arranged annular groove (15) in the concave bearing surface (13) is provided whose radius (R ₁₅ ) is adapted in cross section to the bearing balls (4). Ball roll after Claim 2 , characterized in that exactly one around the bearing axis (A) completely circumferential annular groove (15) is provided as a recess which receives all bearing balls (4) and defines a circular track for the bearing balls (4). Ball roll after Claim 2 , characterized in that a plurality of each partially around the bearing axis (A) encircling annular groove portions are provided which each receive a portion of the bearing balls (4). Ball roll after Claim 2 . 3 or 4 , characterized in that the or each annular groove (15) relative to the nominal position of the running ball center in an angular range of the polar or elevation angle (θ) to the bearing axis of about 25 ° to 55 °, esp. From 30 ° to 45 ° is arranged. Ball roll after one of Claims 1 to 5 , characterized in that the depth of the or each recess (15) is selected so that an inset bearing ball (4) protrudes with a predominant volume fraction over the bearing surface (13) and / or that with vertical bearing axis (A) in the recess (15) remains held. Ball roll after one of Claims 1 to 6 , characterized in that the running ball (2) made of plastic, in particular a polyamide (PA) or polyoxymethylene (POM), and the bearing balls (4) made of metal, in particular made of stainless steel. Ball roll after Claim 7 , characterized in that the housing comprises a first housing part (11) made of tribopolymer, which has the bearing surface (13) with the recess or the recesses (15), wherein the bearing surface (13) preferably in approximately semispherical or semi-dome-shaped is executed, and a second part (12), preferably of tribopolymer, which has the housing opening (14) with a part-spherical retaining surface which forms the housing opening (14), wherein the housing in particular consists of two parts in two parts (11, 12). Ball roller according to one of the preceding claims, characterized in that the bearing ball diameter is in the range of 10% to 35% of the running ball diameter and / or the running ball has a diameter in the range of about 5mm to 50mm. Ball roller according to one of the preceding claims, characterized in that the bearing axis (A) by the nominal position of the Laufkugelmittelpunkts (M) in the housing (11, 12) and the center of the housing opening (14) is predetermined. Using a ball roller according to one of Claims 1 - 10 in an installed position in which the running ball is directed obliquely or vertically downwards. Using a ball roller according to one of Claims 1 - 10 in a conveyor system, in particular in a ball roller table, a roller conveyor of a conveyor line, a transport table or the like., Or in a storage technical system, in particular as a roller storage container or the like. Using a ball roller according to one of Claims 1 - 10 for supporting a movable component of a piece of furniture or a sports or fitness device.

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