DE102013203981B4 - Double row angular contact ball bearing - Google Patents

Abstract

Two-row angular contact ball bearing (1) in which two rows of balls (4, 5) are arranged between at least one bearing inner ring (2) and at least one bearing outer ring (3), the two rows of balls (4, 5) each having a contact angle (α, β) to the radial direction (R) are arranged, wherein the contact angle (α, β) of the two rows of balls (4, 5) are different in size, characterized in that the bearing outer ring (3) in its two axial end portions by a respective conical Inner surface (6, 7) is limited, wherein the diameter of the conical inner surface (6, 7) decreases in the direction of the axial end of the bearing outer ring (3).

Description

The invention relates to a double-row angular contact ball bearing in which two rows of balls are arranged between at least one bearing inner ring and at least one bearing outer ring, wherein the two rows of balls are each arranged at a contact angle to the radial direction and wherein the contact angle of the two rows of balls are different.

Generic angular contact ball bearings are well suited for the transmission of both radial and axial forces. The bearing is designed to transmit axial loads in both axial directions. The contact angle of the two rows of balls are directed towards each other, so that said axial force transmission is ensured in both axial directions. As a contact angle, a value of about 30 ° to the radial direction is often chosen.

The disadvantage here is that as a result of the application of the balls under said contact angle in comparison to pure radial bearings a higher friction is present. This also has corresponding adverse consequences with respect to the temperature development in the bearing and in terms of the life of the lubricant used.

A generic camp is from the JP 2006 194 361 A known. Similar and other solutions show the DE 10 2009 016 901 A1 , the US 2,103,912 A , the JP 2008 138 842 A , the EP 2 503 168 A1 , the JP 2011 252 521 A , the DE 60 2005 003 458 T2 , the JP 2008 128 448 A , the JP 2008 138 841 A , the EP 2 503 169 A1 , the US 4 635 330 A , the US 5,206,993 A. and the DE 602 22 967 T2 ,

The invention has for its object to propose a generic double-row angular contact ball bearings, which has a related improved running behavior. This should initially be possible to absorb higher loads under otherwise unchanged conditions. Furthermore, the camp should be suitable for higher speeds with less temperature development. Then the life of the lubricant used, in particular bearing grease should be increased. Finally, the aim is to achieve a longer service life of the bearing even when it is used under particularly harsh environmental conditions; This is especially intended for use under cavitation effect and high vibrations. This should be achieved in particular in one-sided axial load application a more favorable running behavior of the bearing.

The solution of this object by the invention is characterized in that the bearing outer ring is limited in its two axial end regions by a respective conical inner surface, wherein the diameter of the conical inner surface decreases in the direction of the axial end of the bearing outer ring.

The contact angle of a ball row is preferably between 25 ° and 35 °, ie in the usual range. However, the contact angle of the other ball row is preferably between 10 ° and 25 °, with a particularly preferred range being between 14 ° and 16 °.

The diameter of the balls of the two rows of balls can be the same size. But it is also possible that their diameters are different.

The angle of taper is preferably between 2 ° and 10 °, more preferably between 3 ° and 7 °.

The bearing inner ring is formed trough-shaped in radial section according to a training in its lying between the balls area.

The proposed bearing is preferably used when an application is given, in which the axial loads occur in both axial directions, however, are very different. For the transmission of the higher axial load, the angular contact ball bearing is used, which has the larger contact angle to the radial direction. Meanwhile, the angular contact ball bearing with the smaller contact angle is used for the transmission of the lower axial load.

In order to be able to take this safely into account during assembly, a further development provides that a marking is located in at least one side region of the bearing which makes it clear that the greater axial load must be applied from this bearing side. Said mark can be designed as identification groove; Similarly, a mark on an end face of the bearing is conceivable, indicating in plain text, that here the axial force is to be applied.

Accordingly, the proposal according to the invention specifically aims at an asymmetrical design of the contact angle of the two rows of balls. The one row of balls thus becomes the preferred row of rolling elements, which can transmit axial loads improved.

The proposed bearing allows a higher static and dynamic radial load bearing, since the bearing with the lower contact angle favors the radial load transfer with low friction. It has been shown that a load increase of up to 15% is possible here.

Similarly, the maximum speed of the bearing can be increased, with an increase of about 10% compared to conventional bearings is possible.

It has also been found that the life of the grease can be increased by about 20%. This is due to the reduced friction of the bearing with the lower contact angle.

If the bearing is used for an application, for example, in a cavitation-type pump, increased service life of the bearing resulted, with increases of 20% observed. Accordingly, the runflat property substantially improves.

By said configuration of the side portions of the outer ring and the space between the rows of balls, the free volume is increased, so that more space for lubricant is available. Furthermore, said conical configuration of the bearing outer rings allows for improved retention of the lubricant in the area where it is needed; the lubricating grease or lubricating oil is conveyed so improved in the rolling contact area.

The proposed embodiment has already resulted in a reduction of the temperature in the warehouse by about 3 ° C in concrete applications. Accordingly, the lubrication conditions and the durability of the lubricant improve.

In the drawing, an embodiment of the invention is shown. The single figure shows schematically the radial section through a double-row angular contact ball bearings.

In the figure, the double-row angular contact ball bearing with the reference numeral 1 designated. It has a bearing inner ring 2 and a bearing outer ring 3 ; The bearing rings each have two raceways for the start of balls 4 and 5 that form two rows of balls. It should be noted that it may be necessary for assembly reasons, at least one of the two bearing rings 2 . 3 to share. But that does not change the present principle.

The two rows of bearings and especially the two rows of balls 4 . 5 have respective contact angles α and β.

With α, the contact angle of the left part bearing is designated, this is the angle that takes the designed pressure direction of the power transmission between the bearing inner ring and bearing outer ring to the radial direction R. The contact angle α is present at 30 °.

With β the contact angle of the right part bearing is designated. The contact angle β is here in the embodiment at 15 °.

Accordingly, the left-hand part bearing is suitable for relatively high axial forces, that is, it can high axial loads on the bearing inner ring 2 and the balls 4 on the bearing outer ring 3 be transmitted.

However, this does not apply to the right-hand part-bearing, which can transmit only lower axial loads due to the lower contact angle, but has a more favorable load behavior with respect to radial loads.

To improve lubricant in rolling engagement between the balls and the bearing rings or their raceways to hold, has the bearing outer ring 3 in its axial end conical inner surfaces 6 respectively. 7 with the taper being oriented to close to the axial end.

The angle of conicity is indicated by γ; this is about 4 ° in the embodiment.

Likewise, it also serves the improved supply of lubricant that in the inner ring area between the two rows of balls 4 . 5 a trough-shaped structure 8th is trained. This allows the accommodation of a sufficient amount of lubricant that can serve as a reservoir.

LIST OF REFERENCE NUMBERS

1

double-row angular contact ball bearings

2

Bearing inner ring

3

Bearing outer ring

4

Bullet

5

Bullet

6

conical inner surface

7

conical inner surface

8th

trough-shaped structure

α

contact angle

β

contact angle

γ

Angle of conicity

R

radial direction

Claims (8)

Double row angular contact ball bearing ( 1 ), in which between at least one bearing inner ring ( 2 ) and at least one bearing outer ring ( 3 ) two rows of balls ( 4 . 5 ), the two rows of balls ( 4 . 5 ) are each arranged at a contact angle (α, β) to the radial direction (R), wherein the contact angles (α, β) of the two rows of balls ( 4 . 5 ) are different in size, thereby characterized in that the bearing outer ring ( 3 ) in its two axial end regions by a respective conical inner surface ( 6 . 7 ), wherein the diameter of the conical inner surface ( 6 . 7 ) in the direction of the axial end of the bearing outer ring ( 3 ) reduced. Double-row angular contact ball bearing according to claim 1, characterized in that the contact angle (α) of a ball row ( 4 ) is between 25 ° and 35 °. Double row angular contact ball bearing according to claim 2, characterized in that the contact angle (β) of the other ball row ( 5 ) is between 10 ° and 25 °. Double-row angular contact ball bearing according to claim 3, characterized in that the contact angle (β) of the other row of balls ( 5 ) is between 14 ° and 16 °. Double-row angular contact ball bearing according to one of Claims 1 to 4, characterized in that the diameters of the balls ( 4 . 5 ) of the two rows of balls are the same size. Double-row angular contact ball bearing according to one of Claims 1 to 4, characterized in that the diameters of the balls ( 4 . 5 ) of the two rows of balls are of different sizes. Double-row angular contact ball bearing according to one of claims 1 to 6, characterized in that the angle (γ) of the conicity is between 2 ° and 10 °, preferably between 3 ° and 7 °. Double-row angular contact ball bearing according to one of claims 1 to 7, characterized in that the bearing inner ring ( 4 ) in his between the balls ( 4 . 5 ) lying in a radial section trough-shaped ( 8th ) is trained.

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