Roller bearing with a seal

A rolling bearing has an inner and an outer bearing ring. Each bearing ring has an inner and an outer shell surface. The roller bearing has rolling elements, which roll on raceways provided on the respective shell surfaces of the bearing rings, and a sealing disc connected to one of the bearing rings and operatively connected in a sealing manner to the other bearing ring. To connect the sealing disc to the bearing ring, one of the shell surfaces of the one bearing ring includes a first connecting means and the sealing disc includes a second connecting means. The first connecting means provide a rotating engagement in which the second connecting means engage in a connected state of the bearing ring and the sealing disc.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase of PCT Appln. No. PCT/DE2021/100005 filed Jan. 8, 2021, which claims priority to DE 102020103730.9 filed Feb. 13, 2020, the entire disclosures of which are incorporated by reference herein.

TECHNICAL FIELD

The disclosure relates to sealing of a rolling bearing, more particularly to the fastening of seals to bearing rings of large bearings.

BACKGROUND

In order to protect the bearing space in which the rolling elements roll against external environmental influences and/or to prevent the escape of lubricant located in the bearing space for lubricating the rolling elements, seals can be provided at the axial ends of the bearing rings, one edge of which is connected to one of the bearing rings of the rolling bearing in a non-rotatable manner and the other edge of which, often provided with a sealing lip, is operatively connected in a sealing manner to the other bearing ring.

A seal for a spherical roller bearing is described in DE102013226557 A1, which comprises a sealing disc, one edge of which is provided with a sealing lip made of an elastic material and the other edge of which is connected to one of the bearing rings. According to one embodiment of DE102013226557 A1, the sealing disc and bearing ring are connected by means of a plurality of screws by inserting the screws through holes in the sealing disc and screwing them into threaded holes on the face of the bearing ring. Apart from the fact that this method of fastening the sealing disc requires additional components, namely screws, for fastening, the provision of threaded holes in the bearing ring reduces its strength. In addition, the connection of the scaling disc and bearing ring is very time-consuming due to the tightening of the many screws. According to another embodiment of DE102013226557 A1, the connection between the sealing disc and the bearing ring is effected by providing a dovetail-shaped groove in one of the bearing rings, into which an edge of the sealing disc complementary to the groove is pressed. Even though this embodiment eliminates the need for additional fastening means to secure the sealing disc, the connection is difficult to establish because it requires the sealing disc to be deformed radially inward, which becomes increasingly difficult as the size of the sealing disc increases, even if it is made of a flexible material, and is completely impossible with sealing discs made of metal, which is a very common material.

In addition. U.S. Pat. No. 2,659,617 describes, for example, that the edge of the sealing disc, which is intended to be secured to a bearing ring, is additionally provided with an elastic edge layer. For this purpose, the edge of the sealing disc is elaborately formed together with the elastic edge layer in such a manner that, after the forming step, the elastic edge layer is fixed to the edge of the sealing disc by the forming and, at the same time, the elastic edge layer forms the radially outermost closure of the unit consisting of the scaling disc and elastic edge layer. The scaling disc formed in this way is then connected to the bearing ring in such a manner that the sealing disc is pressed into the bore of the bearing ring, wherein the elastic edge layer is elastically deformed and expands into a circumferential groove provided on the bearing ring after the sealing disc has reached its final position in the bore of the bearing ring.

It is also conceivable to prepare the sealing disc for connection to a bearing ring by injecting an elastic edge layer. Even though this eliminates the need for mechanical forming of the sealing disc, this type of preparation is very costly in terms of equipment needed and is therefore suitable for mass-produced bearings and not for large bearings, which are often only manufactured in very small quantities.

SUMMARY

The disclosure is based on providing an exemplary embodiment of sealing discs for large bearings which can be connected in a simple manner to bearing rings of such large bearings without the need for further components.

It is advantageous if the sealing disc is formed of metal or plastic and is provided with a sealing lip made of rubber or a flexible plastic.

If one of the two shell surfaces of one of the two bearing rings includes a first connecting means and the sealing disc includes a second connecting means, wherein the first connecting means provide a rotating engagement in which the second connecting means engage in a connected state of the bearing ring and the sealing disc, the components intended for connection already provide the respective connecting means required for the connection thereof, i.e., no further components are required to establish a connection between the components intended for connection. This is particularly advantageous because the components intended for connection usually have to be machined, so that the respective connecting means can be formed as well during machining.

The first and second connecting means can be formed together with the manufacture of the two components if the connecting means are formed by threads, because, as is usual with bearing rings, turning operations, for example for machining raceways, have to be carried out anyway and threads can therefore also be formed.

An additional space requirement for the sealing disc connected to the bearing ring is avoided if the bearing ring, which is provided with first connecting means, is provided with a radial shoulder on which the first connecting means are formed and whose diameter is different from the diameter of the inner and outer shell surfaces of this bearing ring.

Complex screwing movements for connecting the sealing disc and the bearing disc are avoided if the first connecting means has a first annular edge and the second connecting means has a second annular edge which is likewise exposed, wherein in the connected state of the respective bearing ring and the sealing disc both annular edges overlap one another in an overlap region Ü when at least the first annular edge is provided with at least one opening, when the second annular edge is formed by at least one shoulder segment, wherein a plane in which the respective shoulder segments lie maintains an axial distance A from a plane of the sealing disc, and the respective openings and respective shoulder segments are complementary to one another.

The connecting means can be secured together via wedging by rotating one annular edge with respect to the other annular edge when each shoulder segment has first and second ends E1, E2in a circumferential direction, wherein axial distances A1, A2of the first and second ends E1, E2of the respective shoulder elements to the plane of the sealing disc are different.

A lubricant leakage between the connecting means is prevented if an O-ring is provided between the sealing disc and an end face of the bearing ring to which the sealing disc is connected

if receptacles are provided on the sealing disc which are suitable for receiving tools and/or grub screws, these receptacles not only facilitate the rotation of the sealing disc relative to the bearing ring during assembly by receiving appropriate tools, but can also be used, when the sealing disc has assumed its end position in the bearing ring, to secure the sealing disc against rotating relative to the bearing ring by screwing in grub screws.

DETAILED DESCRIPTION

FIG.1shows a rolling bearing1, which has an inner bearing ring2and an outer bearing ring3. Each of these two bearing rings2,3has an inner and outer shell surface4,5. These bearing rings2,3are bearing rings of a large bearing, which in the context of this application means outside diameters of more than 320 millimeters (mm), e.g., 600 mm, more than 1,000 mm, etc. Raceways6are provided on the respective inner shell surfaces4of the two bearing rings2,3, on which rolling elements7roll. Even though the rolling bearing1shown here is a spherical roller bearing, the application of the disclosure is not limited to spherical roller bearings, but can also be used with cylindrical roller bearings or tapered roller bearings.

According to the embodiment inFIG.1, the outer shell surface5of the outer bearing ring3is lowered radially inward at its axial ends, thereby providing a radial shoulder8and a ring wall9. As can be seen inFIG.1, the radial shoulder8has a diameter different from both the inner and outer shell surfaces4,5of this bearing ring3. This radial shoulder8is provided with first connecting means in the form of an external thread10.

Furthermore, the embodiment inFIG.1shows a sealing disc11, which is made of metal and is essentially circular in shape. Essentially circular in shape means that the sealing disc11extends circumferentially about an axis even if the sealing disc11deviates from a perfect circle. For the sake of completeness only, it should be noted that in another exemplary embodiment not shown, the sealing disc11can also be formed from a less flexible plastic, such as PEEK. Adjacent to an outer edge12of the sealing disc11is an axial flange13, an inner edge surface14of which is provided with a second connecting means in the form of an internal thread15.

An inner edge16of the sealing disc11is provided with a sealing lip17, which is formed from an elastomer and which abuts against the inner bearing ring2and is thus operatively connected in a sealing manner.

For sealing an annular space18between the two bearing rings2,3, the sealing disc11with its internal thread15provided on the axial flange13is screwed onto the external thread10on the lowered shell surface8of the outer bearing ring3. To facilitate screwing of the sealing disc11onto the outer bearing ring3, a receptacle19in the form of a blind hole is indicated in the sealing disc11, which is suitable for receiving a tool in the form of a rod (not shown) to rotate the sealing disc11relative to the outer bearing ring3.

Even though the lowering of the outer shell surface5of the bearing ring3and the receiving of the axial flange13in the lowering has advantages with respect to the flushness of the rolling bearing1, in another exemplary embodiment not shown, the first connecting means in the form of the external thread10can also be mounted directly on the outer shell surface5of this bearing ring3, which then results in a radial projection of the sealing disc11from the outer shell surface5when the sealing disc11is screwed on.

FIG.2differs from the embodiment according toFIG.1only in that an O-ring21is provided on an end face20of the outer bearing ring3. If the sealing ring11is screwed to the outer bearing ring3in the manner described above, the sealing ring11comes closer and closer to the end face20. If, when the sealing ring11is screwed on, it comes into contact with the inserted O-ring21, the latter will be pressed flat by the sealing ring11when it is screwed on further. This flattening of the O-ring21serves two functions, namely it ensures that no lubricant can leave the annular space18via the screw connection and also that a force is exerted by the O-ring21on the sealing disc11, which prevents a loosening of the screw connection during operation of the rolling bearing1.

Furthermore, the receptacle19according toFIG.2is not merely a blind hole, but a through hole provided with an inner thread22. This inner thread22not only allows a tool (not shown) that can be screwed into the inner thread22to effect the rotation of the scaling disc11relative to the outer bearing ring3to be secured, but when the scaling disc11has assumed its end position on the outer bearing ring3, it can also be used to secure against rotation by screwing in grub screws (not shown).

FIG.3shows a rolling bearing1in the form of a cylindrical roller bearing. The inner bearing ring2is designed without a rib, while the outer bearing ring3is provided with a rib23. Consequently, the inner shell surface4of the outer bearing ring3is formed by the raceway6and a laterally adjacent one radial shoulder8rib shell surface24. The internal thread15is provided in the rib shell surface24as the first connecting means. Furthermore, a sealing layer disc11is shown, with the axial flange13adjoining the outer edge12. An outer edge surface25of the axial flange13is provided with second connecting means in the form of the external thread10.

As already shown in connection withFIGS.1and2, a sealing lip17also adjoins the inner edge16of the sealing disc11inFIG.3. In order to seal the rolling bearing1shown inFIG.3, the sealing disc11is merely screwed into the internal thread15on the rib shell surface24via the external thread10.

For the sake of completeness only, it should be noted that in the case of an outer bearing ring3without a rib23according toFIG.3, the first connecting means in the form of the internal thread15can be cut into the inner shell surface4of the bearing ring3.

The exemplary embodiment according toFIG.4is, in turn, concerned with a rolling bearing1in the form of a spherical roller bearing. In contrast to the embodiment according toFIG.3, an annular groove26is brought into the end face20of the outer bearing ring3, wherein in this exemplary embodiment the radial shoulder8of this annular groove26is provided with first connecting means in the form of the internal thread15. To connect the sealing disc11to the bearing ring3, the axial flange13is provided with the external thread10and screwed to the radial shoulder8of the annular groove26with the internal thread15. Since the axial flange13is received by the annular groove26after screwing and the end face20of the outer bearing ring3is provided with an axial retraction27with respect to the end face20of the bearing ring3and which adjoins the annular groove26radially inwards, the screwed-in sealing disc11closes the rolling bearing1shown in a flush manner, i.e., without axial projection.

As an additional sealing, according to the exemplary embodiment shown inFIG.4, the O-ring21is provided which is inserted into a groove28in the axial flange13and which, after the sealing ring11and bearing ring3have been connected, rests against the ring wall9of the annular groove26. To secure the sealing disc11against rotating after mounting in the bearing ring3, a grub screw29is screwed into a receptacle19formed as a threaded hole.

InFIGS.5atod, the connecting means of bearing ring3and sealing disc11are formed by exposed annular edges.

The first annular edge30is provided on the outer bearing ring3and is formed by the circumstance that, in this exemplary embodiment, a circumferential groove31is formed in the inner shell surface4of this bearing ring3. The first annular edge30thus exposed is provided with openings32, of which, however, only one opening32is shown inFIGS.5a, bandd.

A hook-shaped shoulder segment34is provided on an inner side33of the scaling disc11as shown inFIG.5c, an axial region35of which extends from the inner side33of the sealing disc11and a radial region of which, which forms a second annular edge36, runs along the inner side33of the sealing disc11while maintaining a distance A from the plane formed by the sealing disc11. Although only one shoulder segment34is shown inFIG.5c, in another exemplary embodiment not shown, the sealing disc11can also be provided with two or more shoulder segments34on its inner side33, such that the radial regions of all shoulder segments34ultimately form the second annular edge36of the sealing disc11.

To connect the sealing disc11to the bearing ring3, the sealing disc11(FIG.5c) is pushed onto the bearing ring3(FIG.5b) in the direction of the arrow P1by engaging the respective shoulder segments34in the openings32. For this purpose, the respective shoulder segments34are formed complementary to the respective openings32in the first annular edge30. Once the shoulder segments34have passed through the openings32, conditions are established as shown inFIG.5d, which provides a view of a first end E1of the shoulder segment34inserted into the opening32.

As can be seen from the detailed drawing, which shows a view into the shoulder segment34according toFIG.5c, the shoulder segments34has a first and a second end E1, E2in the circumferential direction, wherein an axial distance A1between the inner side33of the scaling disc11and the second annular edge36at the first end E1is greater than an axial distance A2between the inner side33of the sealing disc11and the second annular edge36at the second end E2.

This positioning of the second annular edge36relative to the inner side33of the sealing disc11can be used to connect the sealing disc11to the bearing ring3in a captive manner, namely by wedging. When the respective shoulder segments34of the sealing disc11are inserted into the openings32in the bearing ring3, the conditions shown inFIG.5dare established. The detail according toFIG.5d, which involves a view in the direction ZZ according toFIG.5d, namely makes it clear that the shoulder segment34shown there, when it has passed through the opening32, faces the first annular edge30defining the opening32in the circumferential direction with its ends E1, E2pointing in the circumferential direction. If the sealing disc11is now rotated counterclockwise (indicated by the arrow P2), the first annular edge30, whose axial width B is smaller than the distance A1, enters into the distance A1. However, since the distance A1in the direction of rotation of the sealing disc11decreases to the distance A2at the end E2of the shoulder segment34and this distance A2is smaller than the axial width B of the first annular edge30, the second annular edge36wedges against the first annular edge30and thus secures the sealing disc11to the bearing ring3.

To improve the sealing effect, the O-ring21is provided, which in this case is arranged in an overlap region U between both annular edges30,36.

LIST OF REFERENCE SYMBOLS