WO2020057783A1

WO2020057783A1 - Ball roller, in particular polymer ball roller, and uses therefor

Info

Publication number: WO2020057783A1
Application number: PCT/EP2019/059993
Authority: WO
Inventors: Marcus SEMSROTH
Original assignee: Igus Gmbh
Priority date: 2018-09-20
Filing date: 2019-04-17
Publication date: 2020-03-26
Also published as: TW202012803A; DE202018105401U1

Abstract

The invention relates to a ball roller (1) comprising a housing (11, 12) and a running ball (2), in particular a polymer running ball, which projects in the direction of a bearing axis (A) through a housing opening (14). A concave bearing surface (13) adapted to the running ball is provided in the housing, on which bearing surface the running ball (2) is mounted by means of a number of intermediate bearing balls (4) having a diameter which is significantly smaller than the diameter of the running ball. According to the invention, the concave bearing surface (13) has at least one recess (15) adapted to the diameter of the bearing ball, and the bearing balls (4) lie in a corresponding recess (15). As a result, the bearing balls (4) are reliably held in a predefined position relative to the running ball (4) in every operating position.

Description

Ball roller, in particular polymer ball roller, and

Applications for this

The invention relates generally to a ball roller with a housing and a running ball in the direction of a

Bearing axis viewed from the housing through a

Housing opening with smaller compared to the ball

Diameter protrudes, one in the housing to the

Ball, adapted, concave bearing surface is provided, on which the ball is rotatably supported by means of a number of smaller balls (hereinafter: bearing balls). The bearing balls are used for rolling bearings and are located between the ball and the bearing surface in the housing and have one

Diameter that is typically significantly smaller than that

Ball diameter.

Such generic ball rollers are used in particular in transport or storage devices e.g. on

Ball roller tables, transport tables, support devices or storage tables used. Often, a large number of ball rollers are arranged in a horizontal plane, so that e.g. a workpiece can be placed and moved in any direction within the plane.

Generic ball rollers can be used e.g. also for storing moving parts, for example on furniture

Workbenches or assembly workplaces etc. or as driving or rollers to wheels for carrying mobile objects.

DE102012100575A1 describes a generic ball roller. A generic ball roller unit for the

Conveyor technology is also described in DE19622903C2, there with resilient support of the ball.

In the known designs, a variety of

Bearing balls for rolling bearing disordered and freely movable between the ball and the bearing surface.

It turned out that the possible

Applications, particularly with regard to the installation position, are restricted by the typical construction. In addition, a smooth, quiet run can only be achieved to a limited extent.

An object of the invention is therefore to propose an improved design of a ball roller, which in

any installation position can be used equally and / or has a more uniform, quieter running behavior.

In a generic ball roller according to the preamble of claim 1, the object is already achieved in that the concave bearing surface at least one to the

Has bearing ball diameter adapted recess, and that the bearing balls in an assigned or

insert the appropriate recess to hold the bearing balls rotatable therein and in a predetermined relative position to or on the outer surface of the ball, in particular to hold the bearing balls against an axial change in position with respect to the bearing axis along the surface of the ball.

The bearing balls can thereby their position relative to

Change the ball only within the space defined by the recess. There can be one for all bearing balls Common contiguous depression or several distributed depressions can be provided for part of the bearing balls. Each specialization must be addressed to the

Bearing ball diameter can be adjusted at least to the extent that the bearing balls protrude at least slightly or predominantly over the recess and thus the adjacent bearing surface, but on the other hand the bearing balls are only movable within the corresponding recess.

This simple optimization of the interior of the housing already has a significant advantage, namely that

Ball roller in every installation position, also e.g. can be used with the bearing axis directed horizontally and obliquely or vertically downwards, because the bearing balls, thanks to this

holding recess (s) always a load-bearing or

Maintain the load-absorbing position relative to the ball. In addition, a comparatively smooth and quiet run can be achieved. In other words, the intended position of the bearing balls is limited to the partial area of the depression or depressions, 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, especially in relation to the ball can change.

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

held .

In a preferred, relatively easy to manufacture

Embodiment is a coaxial to the recess

Bearing axis arranged in the concave bearing surface provided, whose radius in cross section to the

Bearing ball diameter is adjusted so that the bearing balls lie or are held in it with little movement. In this case, in particular exactly one annular groove that runs completely around the bearing axis can be provided as a depression. This can accommodate all bearing balls, i.e. the

Simplify assembly and / or specify a circular raceway for the bearing balls, i.e. allow the balls to be supported evenly in all directions. The recess can represent a kind of circumferential running groove in which the smaller bearing balls run, and these only change their spatial position on this circular path.

Alternatively, it is also conceivable to have a number of recesses in the concave which are spatially distributed around the ball

To provide storage space, e.g. three separate

Ring groove sections or sectors along a

Surface circle of the ball. A distributed arrangement of the wells is down to a 1: 1 assignment

conceivable according to the number of bearing balls, i.e. a separate, separate recess for each individual ball roller.

For a good load absorption or distribution, everyone

Ring groove preferably - based on the nominal position of the

Ball center point - in an angular range of

Polar angle (pole distance angle) or elevation angle (in

Polar coordinates with the center of the ball as the origin and the bearing axis as the pole axis) to the bearing axis of approx. 25 ° to 55 °, in particular 30 ° to 45 °.

The depth or the cross-sectional dimensioning (in the section that contains the bearing axis) of the or each recess can be chosen such that an inserted bearing ball with a predominant volume portion protrudes over the bearing surface in order to avoid unnecessary friction and / or that each

Bearing ball with vertical bearing axis in the The depression remains, which simplifies assembly.

In a particularly preferred embodiment for the service life and lubrication-free operation, a plastic ball is used. The ball can run out

Polyoxymethylene (POM).

The smaller bearing balls are preferably made of metal, especially stainless steel. Do in

Applications, e.g. with strong magnetic fields (e.g. in an MRI), however, glass bearing balls are preferred

used.

With the

Material pairing of POM stainless steel, in particular a POM running ball with stainless steel bearing balls, achieved. The stainless steel bearing balls come with a bearing surface on the first

Paired housing part, which is made of a lubricant-free tribopolymer in order to minimize wear there and increase the service life. .

The housing preferably has a first housing part made of a tribopolymer, which has the bearing surface with the depression or the depressions, and one

Housing part having second part, preferably made of plastic.

The bearing surface is preferably approximately hemispherical or semi-spherical, which is e.g. in the

Injection molding process can be implemented cheaply. The same applies to the second housing part, e.g. one

washer-shaped retaining ring, which is preferred

has partially spherical retention surface for the ball that surrounds the housing opening. Preferably, the housing consists in particular only of the two housing parts, which as

Molded parts in plastic - if necessary, both can be produced inexpensively from a tribopolymer, especially in Injection molding process. This reduces the manufacturing and assembly costs, among other things.

In a mechanically favorable design, the smaller bearing ball diameter is in the range from approx. 10% to 35% of the running ball diameter, in particular in the range from approx. 15% to 25%. Regardless of this, the running ball can have a running ball diameter in the range of approx. 5 mm to 50 mm for typical applications. The main component of the load is removed or derived in the direction of the bearing axis. The bearing axis is mechanically determined by the design of the housing and corresponds geometrically mostly to the line through the specified nominal position of the center point of the ball in the housing and the center of the housing opening, corresponding to the main direction of the load to be carried by the load

Force .

The proposed optimization of the ball roller is suitable for a wide variety of known applications and also for areas of application not previously considered, e.g. in an installation position in which the 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 roller can also be used in one

storage system, such as a rack storage system, e.g. can be used as a roller on a storage container or a pallet.

Furthermore, the ball roller can also be used for the storage of a movable component, in particular a piece of furniture, for example of drawers, pull-outs and the like, or of movable parts of a sports or fitness device. However, the use of the invention is not limited to the application examples mentioned, but rather

basically advantageous.

Further details, features and advantages of the invention result - without restricting the generality of the above teaching - from the following, detailed description of a preferred exemplary embodiment with reference to the attached figures. Here show:

FIG. 1: a vertical longitudinal section through the

Overall structure of a roller according to a first embodiment;

2A-2B: a longitudinal section or a plan view of a

Variant of a housing part for the roller according to FIG. 1; and

3 shows a perspective view of the housing part

according to FIG. 2A-2B.

In FIG. 1, a preferred embodiment of the ball roller is generally designated by reference number 1. The

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 cover-like housing part 12, and a number of bearing balls 4.

The first housing part 11 forms a bearing shell with an approximately hemispherical bearing surface 13, in which the ball 2 is inserted. The ball 2 is on the

Bearing balls 4 according to the principle of a roller bearing

supported or stored. For this purpose, the bearing balls 4 are rotatably mounted in the first housing part 11 with respect to the bearing surface 13. The bearing balls 4 transfer the load from the ball 2 to the bearing surface 13, i.e. on that as

Storage frame serving housing part 11. The two

Housing parts 11, 12 are rotationally symmetrical to the bearing axis A and hold the ball center M of the ball 2 on this bearing axis A.

The diameter of the ball 2 D2 = 2xR2 is considerably larger than the diameter D ₄ = 2x R _{4 of} the bearing balls 4, for example by a factor in the range of about 3-6. The radius R2 of the ball 2 can be in the range of about 2-50mm, preferably 2-25mm, or larger. The radius R13 of the spherical bearing surface 13 is larger than the radius R2 of the ball 2 by a predetermined amount

However, the difference is smaller than the diameter D _{4 of} the bearing balls 4, as can be seen below.

As FIG.l and FIG.2A best illustrate, is in the concave bearing surface 13 as a recess for partial

Recording and guiding the bearing balls 4 an annular groove 15 is provided. The annular groove 15 is toroidal, coaxial to the bearing axis A and completely circumferential.

The annular groove 15 is in cross section at the radius R ₄

Bearing balls 4 adjusted. For this purpose, the radius R _{45 of} the annular groove 15 is dimensioned such that the bearing balls 4 can roll freely in the annular groove 15 with little play.

In the example shown here, exactly one completely circumferential annular groove 15 is provided rotationally symmetrically about the bearing axis 5. Other arrangements, for example several distributed annular groove sections or distributed ones

Recesses for individual bearing balls 4 are conceivable.

The annular groove 15 is preferably arranged in the region of the lower half of the hemispherical bearing surface 13, here approximately at a polar angle (Q) of approximately 40 ° with respect to the

Bearing axis A with the center of the sphere M as the origin. The depth of the annular groove 15 measured from the adjacent one

Bearing surface 13 is selected so that a predominant

Volume portion of the bearing balls 4 protrudes beyond the bearing surface 13 in order to minimize the friction surface of the bearing balls 4 on the bearing surface 13. On the other hand, they should Bearing balls 4 for easy assembly with vertical

aligned bearing axis A remain stable in the recess or annular groove 15.

The annular groove 15 forms a kind of groove in which the

smaller bearing balls 4 run freely and between the

Ball 2 and the first housing part 11 from one

Tribopolymer are held in a desired relative position with respect to the balls 2. The bearing balls 4 are guided in FIG. 1 on the orbit with the polar angle (Q) around the axis A.

Thanks to the recess or annular groove 15, the bearing balls 4 cannot be displaced from their desired nominal position regardless of the applied load (if the load is correct

Application and when assembled). The bearing balls 4, particularly when the ball roller 1 is installed in an inclined or vertically downward position, cannot slide down or into a position that is no longer load-bearing. Furthermore, because of the arrangement and geometry of the recess 15 in a predetermined manner limited position of the bearing balls 4, a comparatively smooth and quiet running of the ball 2 is achieved. Especially in

Comparison to the conventional arrangement with disordered

Bearing balls can also use a smaller number of bearing balls 4, since it is not necessary to fill in the space between the ball 2 and the bearing surface 13.

The ball 2 is preferably made of a commercially available plastic, for example a polyoxymethylene (POM). The bearing balls, however, are preferably made of metal, particularly preferably made of stainless steel. Bearing balls can e.g. standard rolling bearing balls can be used. As a ball 2 can also

standard roller bearings made of plastic can be used.

FIGS. 2A-2B show further details of the housing design. The first housing part 11 is made of a lubrication-free

Trib polymer (tribologically optimized polymer plastic with tribological additives, such as solid lubricants), preferably manufactured using the injection molding process. The

In addition to the bearing surface 13 with the preformed recess or annular groove 15, housing part 11 also forms a flange-like projecting mounting collar 17 on the front face of the cylindrical outer surface and a seat 19 provided in this mounting collar 17 for pressing or fastening the second housing part 12 in a suitable receptacle or Drilling. The second housing part 12 has a partially spherical retaining surface as the housing opening 14, which is arranged symmetrically to the bearing axis A and, after fastening the second housing part 12 in the seat 19, holds the running ball 2 centrally on the bearing axis A with little movement play. As with the material pairing between the ball 2 and the bearing balls 4, a tribologically favorable material pairing can also be selected with respect to the tribopolymer of the housing parts 11, 12 with respect to the ball 2 made of commercially available plastic.

With the design according to the invention in combination with that of the material pairing between the ball 2 and

Bearing balls 4 an overall lubrication-free operation and a very long service life, including due to very low abrasion. The are particularly preferred

Housing parts 11, 12 made of the material "Xirodur B180" from igus GmbH from D-55147 Cologne are used.

With the proposed design, i.a. thanks to the

Compliance with an intended position of the bearing balls 4 finally also enables a higher load absorption. Depending on the dimensioning, loads of several 100 N are possible even with small sizes, e.g. with a

Ball 2 with R2 d 25mm. Applicant:

igus GmbH

51147 Cologne

Ball roller, in particular polymer ball roller, and

Applications for this

Reference list

FIG. 1-3

1 ball roller

2 ball

4 bearing balls (support balls)

11 first housing part

12 second housing part

13 storage space

14 housing opening

15 recess / ring groove

17 assembly collar

19 seat (for housing cover)

A bearing axis

Q polar angle (to the bearing axis)

R radius of the ball

R radius of the bearing balls

R13 radius of the bearing surface

Radius of the ring groove

Claims

Expectations

1. Ball roller (1) with a housing (11, 12) and one

Ball (2), in particular a polymer ball, in the direction of a bearing axis (A) through a

Housing opening (14) protrudes, one to the

Ball-shaped, concave bearing surface (13) in

Housing is provided on which the running ball (2) is supported by means of a number of intermediate bearing balls (4) with a diameter that is significantly smaller than the running ball diameter

characterized in that

the concave bearing surface (13) has at least one recess (15) adapted to the bearing ball diameter

has, and the bearing balls (4) in one

insert the appropriate recess (15) to hold it in a predetermined position relative to the ball (4).

2. ball roller according to claim 1, characterized in that a coaxial to the bearing axis (A) as a recess

arranged annular groove (15) is provided in the concave bearing surface (13), the radius (R ₁₅ ) in cross section the bearing balls (4) is adapted.

3. ball roller according to 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 the bearing balls (4) and a circular raceway for the bearing balls (4).

4. Ball roller according to claim 2, characterized in that several each partially around the bearing axis (A)

Circumferential annular groove sections are provided, each of which accommodates a portion of the bearing balls (4).

5. ball roller according to claim 2, 3 or 4, characterized

characterized in that the or each annular groove (15) relative to the nominal position of the center of the ball in an angular range of the polar or height angle (Q)

Bearing axis of approximately 25 ° to 55 °, in particular from 30 ° to 45 °.

6. Ball roller according to one of claims 1 to 5, characterized

characterized in that the depth of the or each recess (15) is selected so that an inserted bearing ball

(4) with a predominant volume share over the

Bearing surface (13) protrudes and / or that the vertical bearing axis (A) remains in the recess (15).

7. ball roller according to one of claims 1 to 6, characterized

characterized in that the ball (2) made of plastic, in particular a polyamide (PA) or polyoxymethylene (POM), and the bearing balls (4) made of metal, in particular stainless steel.

8. ball roller according to 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), the bearing surface (13) preferably approximately is semi-spherical or semi-dome-shaped, and a second part (12), preferably made

Tribopolymer, which has the housing opening (14) with a partially spherical retaining surface which forms the housing opening (14), the housing

in particular in two parts from both housing parts (11,

12) exists.

9. 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

Has a range of approx. 5mm to 50mm.

10. ball roller according to one of the preceding claims,

characterized in that the bearing axis (A) is predetermined by the nominal position of the center of the running ball (M) in the housing (11, 12) and the center of the housing opening (14).

11. Use of a ball roller according to one of claims 1-

10 in an installed position in which the ball is directed obliquely or vertically downwards.

12. Use of a ball roller according to one of claims 1- 10 in a conveyor system, in particular in a ball roller table, a roller conveyor

Conveyor line, a transport table or the like. , or in a storage system, in particular as a roller, a storage container or the like.

13. Use of a ball roller according to one of claims 1- 10 for mounting a movable component

Piece of furniture or a sports or fitness device.