DE10004584C1 - Cylinder roller bearing; has cylindrical rollers arranged between inner and outer rings and guided by symmetrical crowning in at least part of running tracks or roller surfaces - Google Patents

Abstract

The cylinder roller bearing has a number of cylinder rollers arranged between inner (2) and outer rings. The rings or the rollers are guided by a crowning in at least part of the area of their running tracks (5) or surfaces. The crowning (17) of at least one running track of a ring corresponds at least partly to the crowning of the cylinder roller running surface. The crowning is symmetrical to the middle of the ring or roller. The inner or outer ring is cylindrical over a length (LZ) in the middle area (8) of the running track, which equals half of the roller length. The angle ( alpha ) between the tangent (9) at the running track profile and the axis (13) of the ring decreases continuously and progressively from the transition point (11) of the middle area to the edge area (12) of the running track until the end of the crowning.

Description

The invention relates to a cylindrical roller bearing consisting of an inner ring, an outer ring and a number of cylindrical rollers of a defined roller length arranged between the inner ring and the outer ring.
the inner ring, outer ring and / or cylindrical rollers being spherical in the region of their raceways or running surfaces at least over parts of the raceway or running surface,
wherein the crowning of at least one raceway of the inner or outer ring essentially corresponds at least partially to the crowning of the running surface of the cylindrical roller and
wherein the crown of the raceway or the tread is symmetrical to the center of the rings or to the center of the cylindrical rollers.

A generic cylindrical roller bearing is for example from CH 99 346 known. In a known manner, cylindrical roller bearings are cylindrical Rolling elements positioned between an inner and an outer ring. For the purpose of Avoiding edge tensions or edge stretches can be provided  that the rolling elements are slightly spherical and the associated raceways Rings are designed accordingly.

Cylindrical roller bearings in the so-called NU or in the N design are as Floating bearings used. With these cylindrical roller bearings it is ensured that the cylindrical rolling elements are fixed relative to one of the rings, relative to other ring can move axially. The axial definition of the Rolling element relative to one of the rings is accomplished in that on the Ring ring shelves in question are provided. They run against them Rollers on axial load, so that there is an axial for the rolling elements Leading relative to the ring in question results.

Disadvantageously, cylindrical roller bearings of the types mentioned have one relatively high manufacturing effort required: the contact rims for the rolling elements must be precisely manufactured and ground so that the useful life of the Camp can be reached.

Furthermore, it has been found disadvantageous that the rolling elements bearing cages of cylindrical roller bearings in order to achieve a corresponding Strength must be so large that not the maximum possible number of rolling elements can be installed in the bearing: Since the cage at most the contact shelves can rest, there is a relatively low usable height for the Cage, so that the side rings of the cage are made correspondingly wide have to; there is therefore less space for the rolling elements in the axial direction Available.

The invention is therefore based on the object of a cylindrical roller bearing to further develop the type mentioned at the outset in such a way that it is possible to develop the Reduce manufacturing costs. It should be tried by name on the the lateral guide rims of the cylindrical roller bearings that were previously necessary  waive, although care should be taken to ensure that a sufficient axially fixing or guiding the cylindrical rollers relative to at least one of the Rings done. Furthermore, the camp should be developed in such a way that it can withstand a high load with an extended service life. Finally, the inclination of the cylindrical rollers to lock during the run be minimal.

The solution to this problem by the invention is characterized in that

• - That the inner and / or outer ring over a length in the central region of the Career is cylindrical, the length at least 50%, preferably 70%, the roll length of the cylindrical roller, and
• - that the angle between the tangent to the track profile of the interior or outer ring and the axis of the inner or outer ring from Transition point from the middle area to the edge area of the track to steadily and progressively increases towards the end of crowning.

With the features according to the solution, the aim according to the invention can be achieved become: The specific training of the career has at least one bearing ring the result is that the rolling elements rolling on this track automatically be centered and insensitive to slight axial forces than the cylindrical rollers tend to be, the raceway of the ring is not to leave in the axial direction. A separate fuse to prevent the axial drifting away of the cylindrical rollers relative to the bearing ring, as caused by the there is no known contact shelves; at least it is not necessary, if necessary, but still intended to significantly machine because the rolling elements usually do not contact them. When it ceases to exist the thrust rings also result in a larger diameter for the arrangement of the cage. Due to its increased height compared to previously known  Embodiments, the cage side rings can be narrower with the same strength be built, which gives more space for cylindrical rollers; the camp can consequently be equipped with a larger number of rolling elements than before, which increases both the load-bearing capacity and the service life of the bearing elevated.

Advantageously, the angle between the tangent to the profile of the Inner or outer ring and the axis of the inner or outer ring immediately after the transition point towards the end of the crown between 0.0005 ° and 0.01 °, preferably between 0.001 and 0.005 °. At the end of crowning the angle is preferably between 10 ° and 45 °, in particular between 13 ° and 17 °.

A particularly good stabilization of the cylindrical rollers relative to the corresponding trained race results if it is provided that the increase of the angle is such that at least over parts of the edge area Angle as it progresses in the axial direction by constant lengths is multiplied by a multiplication factor greater than 1; this factor is preferably between 1.5 and 2.5. It is particularly preferably 2.

A particularly favorable profiling of the raceway of the inner or outer ring arises when the length segment at which the multiplication occurs or doubling the angle between the transition point and the end of the Crowning occurs between 0.005 and 0.03 times the roll length is preferably 0.01 times the roll length.

The advantage of the solution according to the invention is particularly evident when if it is provided that the bearing rings have no lateral guide rims exhibit.  

Because of the different Hertzian pressure between the outer ring and Rolling elements and inner ring and rolling elements is preferably thought that the Tread of the outer ring is cylindrical and the tread of the Inner ring is essentially adapted to the contour of the cylindrical rollers. So that will achieved that the critical contact surface between the cylindrical rollers and the inner ring has improved contact geometry, which leads to a longer service life of the Camp leads. With an optimal design of the contact geometry, and outer ring raceway the same Hertzian pressure.

As already shown above, the crowning of at least one track of the interior or outer ring essentially the crown of the tread of the cylindrical roller correspond. However, there are special advantages when working in the micro range Differences in the geometries between the race and cylindrical rollers result. It is particularly preferred that the increase in the angle in the area between the transition point and the end of the crown on the cylindrical roller increases slightly more than on the inner ring or outer ring. Despite this deliberately provided differences in the profile between rolling elements and Raceways of the rings should be in the sense of this patent application the profiles in correspond essentially. The differences correspond to the edge drop of known ones Cylindrical rollers with a logarithmic track profile. The invention Design also leads to the fact that edge stretcher is better avoided, whereby larger misalignments are possible.

In the drawing are exemplary embodiments of the invention Cylindrical roller bearing shown.

Fig. 1 shows schematically the section through a cylindrical roller bearing, in

Fig. 2, the profile of the inner ring of the cylindrical roller bearing is shown schematically in section,

Fig. 3 illustrates the geometry as well as the contact conditions between the outer ring and a cylindrical roller,

Fig. 4 shows schematically the section of a cylindrical roller bearing with a cage, in

FIG. 5 shows the section along line AA according to FIG. 4.

In Fig. 1, a cylindrical roller bearing 1 is shown. It has an inner ring 2 and an outer ring 3 , between which cylindrical rollers 4 are arranged. The inner ring 2 has a raceway 5 on which the cylindrical rollers 4 roll. In an analogous manner, the outer ring 3 has a raceway 6 which is in contact with the running surface 7 of the cylindrical rollers 4 . The cylindrical rollers 4 themselves have a length of L _W.

The raceway 5 of the inner ring 2 is not straight, but spherical. A cylindrical section can be seen in the middle area, but a spherical design 17 of the ring is provided towards the edge area. Correspondingly, the cylindrical roller 4 has a crown 16 in the corresponding section. It should be emphasized at this point that the figure only represents the schematic relationships and that the crowning mentioned actually usually only has a few tenths of a millimeter. As a result, the generic term as cylindrical roller bearing is also correct.

As can further be seen from FIG. 1, the crown 17 is incorporated into the inner ring 2 , while the outer ring 3 is cylindrical. By the crown and the correspondingly largely congruent molded cylindrical roller 4 is achieved that the roller is stably performed in the raceway 5 of the inner ring, while on the cylindrical contact surface between the cylindrical roller 4 and outer ring 3 is an axial Relativverschieblichkeit of the inner ring 2 is possible relative to the outer ring 3 is.

The design of the raceway 5 of the inner ring 2 can be seen in detail in FIG. 2. It should be noted that this representation is also schematic and shows the crowning actually envisaged far too high.

The inner ring 2 has a raceway 5 , which extends over the length L _B. The raceway 5 is formed symmetrically to the center of the inner ring 2 . In the central area 8 , the track 5 has a purely cylindrical section on which the length L _Z extends. The central region 8 ends at a transition point 11 from which the edge region 12 adjoins itself - symmetrically on both sides. The edge region 12 has the crowning 17 in question of the ring, ie between the transition point 11 and the end 14 of the raceway 5 , the spherical section 17 adjoins the middle straight section (in the middle area 8 ).

The crown 17 is designed as follows: Immediately behind the transition point 11 , the profile 10 of the track 5 continues with an angle between 0.0005 ° and 0.01 °, preferably with a value between 0.001 ° and 0.005 °. With each advance in the axial direction 15 from the transition point 11 by a length section ΔL, the pitch angle α multiplies by a predetermined factor. The angle α itself is defined as the angle between the tangent 9 to the profile 10 of the race 5 and the axis 13 of the inner ring 2 .

A value between 1.5 and 2.5 is preferred as the multiplication factor, specifically the value 2, which has the consequence that the angle doubles in the direction of the axis 15 per length section ΔL.

Still oversubscribed, but already largely to scale, FIG. 3 shows the geometric relationships between cylindrical roller 4 and outer ring 3 of a cylindrical roller bearing; in this case, a reverse configuration to Fig. 1 would be provided in that the inner ring - not shown - has a cylindrical raceway and outer ring 3 and cylindrical rollers 4 have the largely congruent spherical shape. It is of course also conceivable that both the inner and outer ring have spherical raceways, which would enable the bearing to transmit significant axial forces.

As can also be clearly seen here, the cylindrical section of the sound track 6 of the outer ring 3 initially continues at a very small angle from the transition point 11 from the central area 8 to the edge area 12 . The transition point 11 is at a distance of 15% of the length of the career L _B from the end 14 of the career.

In the sketched case, the length segments ΔL each amount to 1% of the length L _{B of} the career. That is, per length ΔL multiplies, namely the angle α between tangent 9 and the axis of the ring doubles. This can be seen quite well in the figure, because up to a distance of approx. 5% of the length of the raceway L _B from the end 14 of the raceway, there was only a slight edge shortening of less than 0.05 mm, during the further course until the end 14 of the track progressively increases to a value above 0.5 mm (compare the angles α ₁ and α ₂ in FIG. 3).

Furthermore, it can be seen that despite largely congruence of the raceway 6 of the outer ring 3 and the running surface 7 of the cylindrical roller 4, there are certain slight deviations between the two curves: the increase in the angle α to form the crown 16 of the cylindrical roller takes place somewhat more than the increase in the corresponding angle α to form the crown 17 or curvature of the ring. As can be clearly seen in FIG. 3, this results in a slight gap in the axial direction of the ring or the roller, especially in the end region of the edge region 12 near the end 14 of the raceway. This gradually increasing gap advantageously has the result that when an axial load is applied to the cylindrical roller bearing, the cylindrical rollers 4 with their crowning 16 only gradually contact the crowning 17 of the outer ring 3 . In this way, a gradual introduction of force is achieved and the rolls are not impaired in their rolling behavior. The contact of the rollers with the inner ring begins where the angles (α) are greatest; As a result, the resulting load from the axial load and radial load remains relatively low.

As an example of the configuration of the profile of cylindrical roller and race track is made to the table below, the _R, depending on the distance from the end 14 of the raceway in% of the track width L _B the respective angle of inclination α of the roller 4 and h the edge rise of the cylindrical roller 4 and the Edge increase h _{B of} the raceway 6 of the outer ring 3 shows (compare with the coordinate system in FIG. 3):

As can be seen from the table, the cylindrical region L _{Z of} the profile extends to a distance of 16% of the length L _{B of} the raceway from the end 14 ; the angle α is 0 ° there, there is a gap 16 of 0.001 mm. Immediately behind the transition point 11 at a distance of 15% from L _B , an angle not equal to 0, namely an angle α of 0.002 °, is provided for the first time. Both the edge rise of the roller and that of the ring increase accordingly. As can be seen between the range of 15% of L _B to 4% of L _B , the angle doubles each time the axis extension increases by 1% of L _B. From a position of 4% of L _B , the angle α increases further, but from here no longer with the multiplication factor 2 , but less. It can thus be seen that the multiplication by a predetermined factor does not necessarily have to continue over the entire range, but it is sufficient to provide this procedure for at least a certain section of the track width.

Special mention should also be made of the gradually increasing difference in the edge increase between the role and the career. In the example mentioned (table), the difference between the two edge rises at the end 14 of the raceway is 0.032 mm (0.531 - 0.049 mm).

FIGS. 4 and 5 show the preferred for the novel cylindrical roller bearings come to use cage 18. As can be clearly seen from FIG. 4, the cage 18 guides the cylindrical rollers 4 only at the ends of the pockets, which, in cooperation with the described race design, ensures that the rollers are adequately aligned. As can be seen from the cross section through the bearing - see FIG. 5 - the cage can extend to the inner radius of the outer ring 3 due to the lack of run-in rims, which is why its overall height is significantly greater than that of conventional cages. The side rings can be made narrower, which increases the roll length. The cage webs can be made narrower in the circumferential direction without reducing the connection area to the cage side rings, which creates more space for additional cylindrical rollers which can be integrated into the bearing. This increases the bearing capacity of the bearing.

Reference list

1

Cylindrical roller bearings

2

Inner ring

3rd

Outer ring

4

Cylindrical rollers

5

Race of the inner ring

6

Race of the outer ring

7

Tread of the cylindrical roller

8th

Middle area

9

tangent

10th

profile

11

Transition point

12th

Edge area

13

axis

14

End of career

15

Axis direction

16

Crown of the cylindrical roller

17th

Crown of the ring

18th

Cage
L _W

Length of the cylindrical rollers
L _Z

Center section length
L _B

Length of the career
ΔL length segment
α angle between the tangent and the axis
h _R

Rise of the cylindrical roller edge
h _B

Edge rise of the career

Claims (10)

1. Cylindrical roller bearing ( 1 ), consisting of:

• - an inner ring ( 2 ),
• - An outer ring ( 3 ) and
• - A number of cylindrical rollers ( 4 ) of a defined roller length (L _W ) arranged between the inner ring ( 2 ) and the outer ring ( 3 ),

the inner ring ( 2 ), outer ring ( 3 ) and / or cylindrical rollers ( 4 ) crowned in the region of their raceways ( 5 , 6 ) or raceways ( 7 ) at least over parts of the raceway ( 5 , 6 ) or raceway ( 7 ) 16 , 17 ) are executed,
wherein the crown ( 17 ) of at least one raceway ( 5 , 6 ) of the inner or outer ring ( 2 , 3 ) corresponds at least partially to the crown ( 16 ) of the tread ( 7 ) of the cylindrical roller ( 4 ), and
the crowning ( 16 , 17 ) of the raceway ( 5 , 6 ) or the running surface ( 7 ) being symmetrical to the center of the rings ( 2 , 3 ) or to the center of the cylindrical rollers ( 4 ),
characterized by
that the inner and / or outer ring ( 2 , 3 ) over a length (L _Z ) in the central region ( 8 ) of the raceway ( 5 , 6 ) is cylindrical, the length (L _Z ) at least 50% of the roll length (L _W ) of the cylindrical roller ( 4 ), and
that the angle (α) between the tangent (9) to the raceway profile ( 10 ) of the inner or outer ring ( 2 , 3 ) and the axis ( 13 ) of the inner or outer ring ( 2 , 3 ) from the transition point ( 11 ) of the central area ( 8 ) to the edge area ( 12 ) of the raceway ( 5 , 6 ) to the end ( 14 ) of the crown ( 17 ) increases steadily and progressively. 2. Cylindrical roller bearing according to claim 1, characterized in that the angle (α) immediately after the transition point ( 11 ) in the direction of the end ( 14 ) of the crown ( 17 ) between 0.0005 ° and 0.01 °, preferably between 0.001 ° and 0.005 °. 3. Cylindrical roller bearing according to claim 1, characterized in that the angle (α) at the end ( 14 ) of the crown ( 17 ) is between 10 ° and 45 °, preferably between 13 ° and 17 °. 4. Cylindrical roller bearing according to one of claims 1 to 3, characterized in that the increase in the angle (α) takes place such that the angle (α) at least over parts of the edge region ( 12 ) as it progresses in the axial direction ( 15 ) by constant Longitudes (ΔL) is multiplied by a multiplication factor greater than 1. 5. Cylindrical roller bearing according to claim 4, characterized in that the Multiplication factor is between 1.5 and 2.5. 6. Cylindrical roller bearing according to claim 4 or 5, characterized in that the multiplication factor is 2 . 7. Cylindrical roller bearing according to one of claims 4 to 6, characterized in that the longitudinal section (ΔL), in each of which the multiplication or doubling of the angle (α) between the transition point ( 11 ) and the end ( 14 ) of the crown ( 17 ) is between 0.005 times to 0.03 times the roll length (L _W ), preferably 0.01 times the roll length (L _w ). 8. Cylindrical roller bearing according to one of claims 1 to 7, characterized in that the bearing rings ( 2 , 3 ) have no lateral guide rims. 9. Cylindrical roller bearing according to one of claims 1 to 8, characterized in that the tread ( 6 ) of the outer ring ( 3 ) is cylindrical and the tread ( 5 ) of the inner ring ( 2 ) is at least partially crowned ( 17 ) and essentially the contour of the cylindrical rollers ( 4 ) is adapted. 10. Cylindrical roller bearing according to one of claims 1 to 9, characterized in that the increase in the angle (α) in the area between the transition point ( 11 ) and the end ( 14 ) of the crown ( 17 ) on the cylindrical roller ( 4 ) increases slightly more than on the inner ring ( 2 ) or outer ring ( 3 ).