EP1819931A1

EP1819931A1 - Antifriction bearing unit

Info

Publication number: EP1819931A1
Application number: EP05814815A
Authority: EP
Inventors: Mathias NÖTH; Baozhu Liang
Original assignee: SKF AB
Current assignee: SKF AB
Priority date: 2004-12-07
Filing date: 2005-11-22
Publication date: 2007-08-22
Also published as: DE102004058904A1; WO2006061096A1

Abstract

The invention relates to an antifriction bearing unit which comprises an inner ring, an outer ring and interposed antifriction bodies, sealing means for limiting the space between the inner and the outer ring accommodating the antifriction bodies, at least one groove that radially extends on the outer surface of the outer ring and that receives an O ring; and at least one centrifugal disk fastened to one of the two faces of the inner ring.

Description

rolling bearing unit

The invention relates to a rolling bearing unit.

In rolling bearings seals are used both to protect the bearing before the entry of solids such as dust and / or liquids such as water and to protect the environment of the bearing against the escape of lubricant from an interior of the bearing. The seals act between an intended stationary and a moving part of the bearing. A distinction is made between non-contact and abrasive seals.

For example, from DE 197 00 135 Al, it is known to use a deep groove ball bearing with single and multiple sealing and previously fixed axially fixed centrifugal disc for a shaft bearing, especially in the ground-level range of agricultural tillage machines, the centrifugal disc in a designated groove on an outer shell of a Roller bearing inner ring is pressed in such a way that it is arranged immovably positively against axial pushing away from its associated seat and protective position.

An object of the invention is to provide a rolling bearing unit, which is formed in dense and dense installation in a predetermined installation environment is.

The object is solved by the subject matter of claim 1. Advantageous embodiments are described in the subclaims.

According to claim 1, a roller bearing unit comprises the following features: an inner ring, an outer ring and rolling elements arranged therebetween, sealing means for limiting a space between the inner and outer ring, which includes the rolling elements, at least one radially encircling groove on the outer surface of the outer ring for receiving an O ring shaped sealing ring and at least one, attached to one of the two end faces of the inner ring slinger.

Characterized in that the rolling bearing unit sealing means for limiting the rolling body-containing space between the inner and outer ring and on at least one of the end faces of the rolling bearing unit this sealing means comprises a directly upstream, attached to the end face of the inner ring slinger is a simple and compact design a Self-sealing rolling bearing provided, on the one hand prevents leakage of lubricant, which is provided for example in the rolling body-containing space and / or on one side of the rolling bearing unit, and on the other hand, an entry, for example, from grinding dust in the lubricated area inside. The centrifugal disc reinforces the sealing effect of the sealant without causing additional friction moments. Furthermore, the centrifugal disc acts as an additional wear protection for the sealant, since, for example dirt particles are kept away from the sealing means by the centrifugal disc, which is particularly advantageous when forming the sealant as a contact fitting sealing washers. Furthermore, prevents in the radially on the outer surface of the outer ring circumferential

Nut inserted O-shaped sealing ring during installation of the bearing unit in a corresponding bearing housing, that in particular when forming the bearing housing made of a material having a thermal expansion coefficient of the of

Outer ring different, in particular larger, a passage of said lubricant and grinding dust, or of foreign matter in general, takes place between the outer shell of the outer ring and the housing. In this case, for example, the outer ring of a bearing steel and the housing is formed of an aluminum alloy.

Characterized in that the centrifugal disc is fixedly secured to the end face of the inner ring, the rolling bearing unit is essentially completely deliverable without any loss of items and assembled without further assembly. Also, the inserted into the corresponding groove of the outer ring O-shaped sealing ring can be supplied so captive.

In an advantageous embodiment, the sealing means and the centrifugal disc are axially spaced so tightly spaced on at least one of the bearing faces, that between the sealing means and the centrifugal disc additionally a kind of labyrinth seal effect is achieved, whereby advantageously the seal is additionally improved.

In an advantageous embodiment, the groove is arranged offset with respect to a radially extending center plane of the rolling bearing unit. As a result, the outer ring is advantageously free of mechanical weakening in the region in which the force transmission between the rolling elements and the outer ring takes place.

Further advantages, features and details of the invention will become apparent from the in the following described exemplary embodiments of the invention with reference to FIGS. Showing:

Figure 1 is an upper half of a longitudinal section through a rolling bearing unit with two centrifugal discs, with an O-shaped sealing ring in a groove of the

Roller bearing outer ring and two cover plates as a sealant for a rolling body-containing space between the two rolling bearing rings and

Figure 2 is an upper half of a longitudinal section through a rolling bearing unit with two centrifugal discs, with an O-shaped sealing ring in a groove of the rolling bearing outer ring and two sealing washers for sealing a rolling body-containing space between the two rolling bearing rings.

FIG. 1 shows, as an embodiment of the invention, an upper half of a longitudinal section through a roller bearing unit designed essentially as a deep groove ball bearing. The rolling bearing unit comprises an inner ring 10 and an outer ring 20, between which are designed as balls and guided in a cage 40 rolling elements 30 for rolling between the two rings 10 and 20 are arranged.

For closing a space between the rings 10 and 20 containing the rolling bodies 30, a respective disk-shaped cover disk 50, for example formed from a steel sheet, is arranged axially on both sides of the rolling bodies 30 as sealing means. Said space may be at least partially filled with a lubricant, such as a grease. Each of the cover plates 50 is used for attachment to the outer ring 20 with its radially outer edge region in a ring on the inner surface of the outer ring 20 circumferential groove. The cover plates 50 and the inner ring 10 are designed such that each cover plate 50 between a radially inner edge region of the cover plate 50th and an outer jacket of the inner ring 10, a ring-like gap predeterminable radial thickness is formed.

Furthermore, at each of the two end faces of the inner ring 10 are each a disc-like centrifugal disc 60, for example, from a steel sheet, secured by welding the centrifugal disc 60 with the end face of the designated intended for rotation inner ring 10. As a result, in particular the aforesaid space is additionally protected against the penetration of substances coming from the outside, for example grinding dust, in addition to the cover disks 50. In this case, the centrifugal disks 60 are formed with an inner diameter greater than a maximum inner diameter of the inner ring 10 and with an outer diameter approximately corresponding to a diameter of the Wälzkörperteilkreises. Furthermore, on each of the end faces of the inner ring 10, the centrifugal disk 60 and the cover disk 50 are spaced so short in the axial direction that thereby a kind of labyrinth seal effect is achieved, which again produces an additional sealing effect.

Furthermore, an annular circumferential groove 25 is incorporated on the outer surface of the outer ring 20, in which a correspondingly formed O-shaped sealing ring 70 is inserted. It is a function of the sealing ring 70 to achieve sealing in an installation of the rolling bearing unit in a housing, not shown, between the outer shell of the outer ring 20 and a surface of the housing opposite the outer surface. This prevents that from a first space, which adjoins one of the end faces of the rolling bearing unit, occurring there first material, for example, said sanding dust, nor from a second adjoining the other end room space there inserted second material, such as a lubricant into which each other room can enter. This is particularly advantageous when the outer ring 20 and the housing are formed from materials of different thermal expansion coefficients - which is usually the case - because otherwise due to the Thermal expansion would arise depending on the temperature between the outer shell of the outer ring 20 and the opposite surface of the housing, a gap could pass through the aforementioned substances. In this case, the outer ring 20 is typically formed of a bearing steel and the housing, for example, of an aluminum alloy.

FIG. 2 shows, as a further exemplary embodiment of the invention, an upper half of a longitudinal section through a further rolling bearing unit, wherein this rolling bearing unit of FIG. 2 differs essentially from the rolling bearing unit of FIG. 1 in that sealing disks 50 'are used instead of the cover disks 50, wherein each of the sealing washers 50 'comprises a support body 54' and an elastomeric body 52 'cast thereon. In this case, the sealing discs 50 'with respect to the inner ring 10' arranged free of contact, so that between the sealing disks 50 'and the inner ring 10' annular gaps of predeterminable thickness are formed.

In other embodiments, sealing washers are formed with one or more sealing lips for abrading abutment on substantially radially and / or axially extending surfaces of the inner ring. For this purpose, reference is made in particular to the embodiments of sealing disks shown in the SKF General Catalog of June 2003 on pages 229 and 293.

Otherwise, what has previously been described with reference to FIG. 1 applies correspondingly to FIG. 2, wherein components of FIG. 2 corresponding to components of FIG. 1 are designated by the same reference numerals supplemented by a hyphen. Beziigszeichenliste

10, 10 'inner ring

20, 20 'outer ring

25, 25 'groove

30, 30 'rolling elements

40, 40 'cage

50 cover disc

50 'sealing washer

52 'elastomeric body 54' supporting body

60, 60 'slinger

70, 70 'sealing ring

Claims

P ate demand for the rolling bearing unit

1. Rolling bearing unit comprising the following features:

An inner ring, an outer ring and interposed rolling elements,

- Sealing means for limiting a rolling body-containing space between the inner and the outer ring, - At least one radially encircling groove on the outer surface of the outer ring for receiving an O-shaped sealing ring and

- At least one, attached to one of the two end faces of the inner ring slinger.

2. Rolling bearing unit according to claim 1, wherein the rolling bearing unit comprises two centrifugal discs, one of which is attached to one and the other on the other of the two end faces of the inner ring.

3. Rolling bearing unit according to one of claims 1 or 2, wherein at least one of the centrifugal discs is formed like a disc and whose

Inner diameter is greater than a maximum inner diameter of the inner ring.

4. rolling bearing unit according to one of claims 1 or 3, wherein an outer diameter of at least one of the centrifugal discs is greater than a maximum outer diameter of the inner ring.

5. Rolling bearing unit according to one of claims 1 to 4, wherein an outer diameter of at least one of the centrifugal discs corresponds approximately to a diameter of the Wälzkörperteilkreises.

6. Rolling bearing unit according to one of claims 1 to 5, wherein at least one of the centrifugal discs is formed and arranged free of radial overlap with the inner and / or outer ring.

7. Rolling bearing unit according to one of claims 1 to 6, wherein at least one of the centrifugal discs is integrally connected to the end face of the inner ring.

8. Rolling bearing unit according to one of claims 1 to 7, wherein at least one of the centrifugal discs by welding, soldering, gluing or

Caulking is attached to the front of the Innenririgs.

9. Rolling bearing unit according to one of claims 1 to 8, wherein the sealing means comprise at least one perforated disk-like element.

10. Rolling bearing unit according to claim 9, wherein the element is attached to the outer ring such that it forms a predeterminable annular gap relative to the inner ring or bears against the inner ring touching.

11. Rolling bearing unit according to claim 10, wherein the element for the contacting concerns with at least one sealing lip is formed.

12. Rolling bearing unit according to one of claims 9 to 11, wherein the element is so short with respect to the associated centrifugal disc in the axial direction, that a kind of labyrinth sealing effect is achieved by the arrangement of the element and the centrifugal disc.

13. Rolling bearing unit according to one of claims 1 to 12, wherein the groove is arranged offset with respect to a radially extending central plane of the rolling bearing unit.

14. Rolling bearing unit according to one of claims 1 to 13, wherein the rolling elements are designed as balls.

15. Rolling bearing unit according to one of claims 1 to 14, wherein the rolling elements and rings are designed in the form of a deep groove ball bearing.

16. Rolling bearing unit according to one of claims 1 to 15, wherein the rolling bearing unit is provided for installation in a housing whose thermal expansion coefficient is different, in particular greater than that of the outer ring.