Patent Application
20210317879
This application claims priority to German patent application no. 10 2020 204 525.9 filed on Apr. 8, 2020, the contents of which are fully incorporated herein by reference.
The present disclosure is directed to a bearing including a cover for improving lubricant retention and toward a bearing assembly including the bearing.
In certain applications, such as, for example, in textile machine engineering, rolling-element bearings may be subjected to centrifugal forces. This can happen, for example, when the rolling-element bearings are mounted on devices that are themselves set into rotation. If the axis of rotation of the device is perpendicular to the axis of rotation of the rolling-element bearing mounted on the device, the centrifugal forces exerted on the rolling-element bearing can cause a lubricant needed for the frictionless operation of the bearing to pressed out in the axial direction of the rolling bearing due to the centrifugal forces exerted on the lubricant.
A number of conventional seal elements are known that are designed to seal a bearing interior of a rolling-element bearing. However, in particular when the rotational speeds of the device on which the rolling-element bearing is mounted are relatively high, lubricant can be pressed our of the rolling-element bearing despite the presence of known seal elements. This can lead to inadequate lubrication in the rolling-element bearing, as a result of which the service life of the bearing can be reduced.
It is therefore an aspect of the present disclosure to provide a rolling-element bearing that has an improved service life even when the rolling-element bearing is subjected to centrifugal forces in the axial direction.
The disclosed rolling-element bearing comprises an outer ring and an inner ring disposed coaxially thereto which between them define a bearing interior. At least one row of rolling elements is disposed in the bearing interior. The inner ring further comprises a bore in which a shaft is receivable that is connectable to the inner ring for conjoint rotation therewith.
In order to improve the service life of the rolling-element bearing even when the rolling-element bearing is subjected to centrifugal forces in the axial direction, a cover extending end-side on the rolling-element bearing is attached to the outer ring, which cover covers the bearing interior, the inner ring, and the bore. Here the cover can be adapted to reduce or even to prevent a lubricant loss, in particular when the rolling-element bearing is subjected to centrifugal forces. By reducing if not actually preventing lubricant loss, insufficient lubrication in the rolling-element bearing can be delayed or prevented, and the service life of the rolling-element bearing can thereby be increased.
Balls, for example, can be provided as rolling elements. However, other types of rolling elements can be used, such as, for example, cylinders, tapered rollers, barrels, and the like. The rolling elements can be manufactured from metal, in particular rolling-element bearing steel, or ceramic. Alternatively rolling elements made of two different materials, such as, for example, rolling-element bearing steel and ceramic, can be used together in the rolling-element bearing. The rolling-element bearing can be, for example, a deep groove ball bearing. However, the rolling-element bearing can also be a different type of rolling-element bearing such as, for example, a cylindrical roller bearing, a tapered roller bearing, or the like.
Seal elements can additionally be provided independently of the cover that seal the bearing interior. Alternatively the shaft can also be formed integrally with the inner ring, or the rolling elements can slip against the shaft.
A gap is preferably formed between an end surface of the bearing inner ring and the cover so that the cover is spaced from end surface of the bearing inner ring or does not abut against the end surface of the bearing inner ring. This has the advantage in particular that friction between the cover and end surface of the bearing inner ring, which occurs when either the inner ring or the outer ring is set in rotation, can be prevented. For example, a recess can be provided in the cover. Additionally or alternatively the end surface of the bearing inner ring can also be recessed relative to the cover.
According to a further exemplary embodiment the cover can be releasably attached to the outer ring. This has the advantage that the cover remains accessible for maintenance work and/or relubrication.
In order to releasably attach the cover to the outer ring, one or more recesses are preferably formed on the outer ring, and one or more projections configured complementary to recesses are formed on the cover, wherein in the assembled state the projections engage in the recesses. Preferably an encircling groove is provided on the outer ring, and an encircling rib is provided on the cover.
Alternatively one or more recesses, preferably an encircling groove, can be formed on the cover, and one or more projections, preferably an encircling rib, configured complementary to the recesses can be formed on the outer ring, wherein in the assembled state the projections engage in the recesses in order to releasably attach the cover to the outer ring.
Using the one or more recesses or groove, and the projections or rib configured complementary to the recesses, the cover can be attached to the outer ring in a simple and reliable manner. The at least one recess is preferably disposed in a radially inner surface of the outer ring and extends essentially radially outward. In particular the groove can be a groove that is already provided for a seal element for sealing the bearing interior in the radially inner surface of the outer ring.
According to one preferred embodiment, one or more undercuts are formed on the recess, and one or more snap lugs configured complementary to the undercut are formed on the projection, wherein in the assembled state the undercuts and snap lugs engage so that the cover is attached to the outer ring in a self-retaining manner. This has the advantage that the cover can be easily and quickly snapped into the recess. In particular, if a groove is already provided in the outer ring, the rolling-element bearing can be retroactively equipped with a cover.
The cover is preferably manufactured, injection molded, for example, from a plastic material. The plastic material is advantageously chosen such that it has a certain elastic deformability that allows the cover to snap onto the outer ring, in particular into the groove.
A further aspect of the disclosure comprises a textile machine including a device that is configured to rotate about an axis, wherein on the device at least one shaft is provided that is supported by at least one rolling-element bearing described above, wherein an axis of rotation of the at least one rolling-element bearing is perpendicular to the axis of rotation of the device. Here in particular the rotational speed of the device can be 10 to 20 times higher than the rotational speed of the rolling-element bearing.
Further advantages and advantageous embodiments are specified in the description, the drawings, and the claims. Here in particular the combinations of features specified in the description and in the drawings are purely exemplary, so that the features can also be present individually or combined in other ways.
In the following the invention is described in more detail using the exemplary embodiments depicted in the drawings. Here the exemplary embodiments and the combinations shown in the exemplary embodiments are purely exemplary and are not intended to define the scope of the invention. This scope is defined solely by the appended claims.
In the following, identical or functionally equivalent elements are designated by the same reference numbers.
The rolling-element bearing 1 comprises an outer ring 2 and a coaxial inner ring 4. Between the outer ring 2 and the inner ring 4 a bearing interior is defined in which at least one row of rolling elements 6, in this case balls, are disposed. The inner ring 4 further includes a bore 8 (
In order to improve the service life of the rolling-element bearing 1 even when the rolling-element bearing 1, as indicated in
In the embodiment shown in
In the exemplary embodiment shown in
Furthermore, a gap 28 is formed between an end surface 26 of the bearing inner ring 4 and the cover 14 so that the cover 14 is spaced from end surface 26 of the bearing inner ring 4. For this purpose, as can be seen in
In one alternative exemplary embodiment of the end surface 14 that is shown in
The cover 14 can be manufactured from plastic by an injection-molding process. The plastic material is advantageously chosen such that it has a certain elastic deformability that makes it possible to allow the cover 14 to snap into the groove 16.
In order to prevent this loss of lubricant when the rolling-element bearings 1 are subjected to centrifugal forces by the rotation of the device 40, the rolling-element bearings 1 are each provided with a cover 14. By substantially reducing, if not actually preventing a lubricant loss, an insufficient lubrication in the rolling-element bearing 1 can be delayed or prevented, whereby the service life of the rolling-element bearing can be increased.
Overall, due to the attaching on the outer ring of a cover 14 that extends from an end of the bearing and covers the bearing interior, the inner ring 4, and the bore 8, a lubricant loss due to centrifugal forces that affect the rolling-element bearing in the axial direction can be at least reduced if not prevented. In particular this can increase the service life of the rolling-element bearing. In addition, the cover is simple to manufacture and can be simply attached to the outer ring. Grooves already present on the outer ring can be used for this purpose so that already existing bearings can also be retrofitted and new bearings do not need to be additionally processed.
Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved rolling-element bearings.
Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.
All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102020204525.9 | Apr 2020 | DE | national |
