Patent Application
20250215929
The present invention relates to bearings, and more particularly to separators for ball bearings.
Cages for ball bearings are well known and typically include an annular body with a plurality of circumferentially-spaced pockets, each pocket receiving a separate one of the balls of the bearing. The cage establishes a desired spacing between adjacent balls and guides them as they traverse a pitch circle defined between the bearing inner and outer rings. In certain applications, separators are used instead of cages and typically include an annular body with a single pocket that fits about an individual ball. Generally, a plurality of the separators are installed about half of the balls in a set of balls, with every other ball merely contacting two adjacent separators, such that the separators establish a desired spacing between the balls.
Typically, such separators have an outer circumferential surface that is either cylindrical or partially spherical. As a result, the “loose” balls disposed between each pair of adjacent separators tend to contact the outer surface of each separator at a specific point, which focuses the contact pressure and loading applied to the separator and may eventually lead to failure of the separator. Also, as an insufficient amount of lubricant is often supplied to bearings by the end users thereof, in order to avoid contamination from lubricant escaping the bearing, separators may also fail for lack of adequate lubrication.
In one aspect, the present invention is a separator for a ball bearing, the ball bearing including inner and outer rings and a plurality of balls disposed between the inner and outer rings. The separator comprises an annular body having a centerline, opposing first and second axial ends, an inner circumferential surface defining a central pocket sized to receive one of the plurality of balls, and a concave outer circumferential surface. The concave outer circumferential surface defines an annular channel and is configured to contact at least one adjacent one of the balls at a plurality of contact sections spaced axially apart between the axial ends or along a curved line extending at least partially between the first and second axial ends.
In another aspect, the present invention is again a separator for a ball bearing, the ball bearing including inner and outer rings and a plurality of balls disposed between the inner and outer rings. The separator comprises an annular body having a centerline, opposing first and second axial ends, an inner circumferential surface defining a central pocket sized to receive one of the plurality of balls and an outer circumferential surface. A plurality of axially-spaced annular grooves extend radially inwardly from the outer circumferential surface and circumferentially about the centerline, each groove being configured to contain lubricant.
In a further aspect, the present invention is a bearing assembly comprising an inner ring having a centerline, an outer ring disposed about the inner ring, a number N of balls disposed between the inner and outer rings and spaced circumferentially about the centerline so as to define a pitch circle and a number X of separators, the number X being equal to one half a value of N. Each separator includes an annular body having a centerline, opposing first and second axial ends, an inner circumferential surface defining a central pocket sized to receive one of the plurality of balls, and an outer circumferential surface. The outer circumferential surface is concave, defines an annular channel and is configured to contact at least one adjacent one of the balls at a plurality of contact sections spaced axially apart or along a curved line extending at least partially between the first and second axial ends and/or a plurality of axially-spaced annular grooves extend radially inwardly from the outer circumferential surface and circumferentially about the centerline, each groove being configured to contain lubricant.
The foregoing summary, as well as the detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, which are diagrammatic, embodiments that are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Certain terminology is used in the following description for convenience only and is not limiting. The words “inner”, “inwardly” and “outer”, “outwardly” refer to directions toward and away from, respectively, a designated centerline or a geometric center of an element being described, the particular meaning being readily apparent from the context of the description. Further, as used herein, the words “connected” and “coupled” are each intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.
Referring now to the drawings in detail, wherein like numbers are used to indicate like elements throughout, there is shown in
The separator 10 basically comprises an annular body 12 or “toroid” having a centerline LC, opposing first and second axial ends 12a, 12b spaced axially along the centerline LC, an inner circumferential surface 14 and an outer circumferential surface 16. The annular body 12 is diametrically sized to establish a spacing distance between adjacent balls 4, as discussed in further detail below. Preferably, the annular body 12 is formed of a molded polymeric material, most preferably including polyetheretherketone (“PEEK”) and reinforcing fibers (e.g., glass fibers), but may be formed of any other appropriate materials.
Further, the inner circumferential surface 14 defines a central pocket 18 sized to receive one of the plurality of balls 4 and is preferably cylindrical. However, the inner surface 14 may alternatively be generally concave and extend radially outwardly into the body 12, so as to generally match the profile of the balls 4, or have any other appropriate shape or contour. Furthermore, the first axial end 12a of the annular body 12 is configured to be slidably disposed upon an outer circumferential surface 2a of the bearing inner ring 2 and/or the second end axial end 12b of the annular body 12 is configured to be slidably disposed against an inner circumferential surface 3a of the bearing outer ring 3. Such contact with the surfaces 2a, 3a of the rings 2, 3 retains each separator 10 disposed centrally about the particular ball 4 disposed within the pocket 18.
More specifically, the first axial end 12a provides an inner retention surface configured to be slidably disposed upon at least one inner guide surface 2a of the bearing inner ring 2 and the second axial end 12b provides an outer retention surface configured to be slidably disposed against at least one outer guide surface 3a of the bearing outer ring 3. Such guide surfaces 2a, 3a are typically provided by a pair of annular shoulders 2b, 3b adjacent to the inner race RI and the outer ring race RO, respectively, as indicated in
Referring to
More specifically, the concave outer circumferential surface 16 has a radius of curvature RCS (
However, the annular body 12 preferably further includes a plurality of annular grooves 22 spaced axially apart, each annular groove 22 extending radially inwardly from the concave outer circumferential surface 16 and circumferentially about the centerline LC. Preferably, each groove 22 extends entirely about the body centerline LC, so as to be continuous, but may alternatively be non-continuous and arcuate, and be either axially aligned or axially staggered. In any case, with the grooves 22, the annular body 12 thereby also includes a plurality of annular ribs 24 spaced axially apart, each groove 22 being defined between a separate pair of adjacent ribs 24. As best shown in
Referring particularly to
Further, each one of the plurality of annular grooves 22 is configured to contain lubricant, such as grease, heavy oil, etc., and as such, the separator 10 preferably further comprises a quantity of lubricant L disposed within at least one of, and preferably all of, the annular grooves 22, such lubricant L being shown contained within a single groove 22 in
More specifically, due to circumferential clearance between each “loose” ball 4, i.e., a ball 4 not disposed within the pocket 18 of a separator 10, and each adjacent separator 10, the loose balls 4 alternatively contact both adjacent separators 10 during rotation of the ballset 5. That is, although the entire ballset 5 rolls about the bearing pitch circle PC in a single angular direction, the circumferential clearance results in the loose balls 4 intermittently contacting both adjacent separators 10, creating a “pumping” effect that tends to distribute lubricant from the separator grooves 22 to the loose balls 4, and thereafter to the raceways RI, RO, and to the balls 4 contained within the separator pockets 18.
Referring to
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.
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. The invention is not restricted to the above-described embodiments, and may be varied within the scope of the following claims.
