The present disclosure generally relates to the field of bearing assemblies, and more specifically relates to retainer cages for bearing assemblies.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The current trend in automotive industries is to improve fuel efficiency by reducing frictional losses of components of the automotive and reducing effective weight of different components for high speed applications, such as rolling element bearings. At high speed rotation, rolling element bearings fail to perform optimally due to design constraints of conventional retainer cages, weight and insufficient lubrication. Further, at high rotational speeds due to the centrifugal forces subject a retainer cage to stresses. The stresses tend to deform the retainer cage. Deformation of the retainer cage has a detrimental effect on the operation of the rolling elements, thereby leading to accelerated degradation of the rolling elements.
Further, the mating components of the bearings are lubricated by means of a lubricant film. However, while in operation, the lubrication fluid produces a thin lubricant film that fails to reduce the friction between the components of rolling elements at increased speed. Bearing surfaces further deteriorate and increases the probability of wear and the subsequent premature failure of the bearings. Further, the fatigue life of the bearings is reduced due to friction between the components of the rolling element bearing.
In a conventional roller bearing cage the weight of the bearing cage is reduced through reduction in the outer diameter of an axial part or by removing material by providing openings and hollow regions. The reduction in weight is made to reduce the mass of the bearing cage and to enhance the performance of the roller bearing at high rotational speeds.

However, the conventional cage leads to deformations at high rotational speeds. Further, the conventional cages do not provide any provision for enhanced lubrication of the components of the roller bearing.
There is therefore, felt a need for a retainer cage for rolling element bearings that alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure are described herein below:
An object of the present disclosure is to provide a retainer cage for rolling elements that increases useful life of bearing.
Another object of the present disclosure is to provide a retainer cage for rolling elements that improves mechanical properties of bearing assemblies.
Still another object of the present disclosure is to provide a retainer cage for rolling element bearings that has improved design considerations.
Yet another object of the present disclosure is to provide a retainer cage for rolling element bearings that facilitates smooth flow of lubricant.
Yet another object of the present disclosure is to provide a retainer cage for rolling element bearings that helps in reducing rolling friction.
Still another object of the present disclosure is to provide a retainer cage for rolling element bearings that is lightweight yet sturdy.
Yet another object of the present disclosure is to provide a retainer cage for rolling element bearings that provides enhanced performance at high speeds.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY
The present disclosure envisages a retainer cage for rolling element bearings. The retainer cage comprises an annular ring, a plurality of projections, and a pocket. The plurality of projections is extending from the annular ring axially. Each of the projections has pair of arms configured at its tip. Each of the pair of arms defines a space with adjacent pair of arms. The space is configured to receive the rolling element. The pocket is defined in an inner surface of each of the projections. The pocket is configured to store a lubricant therein. The pocket is configured to facilitate lubrication of the bearing elements. The cage is configured to reduce deflection and deformation of the bearing assemblies at higher speeds.
In yet another embodiment, the ring is defined by an inner circumferential surface, an outer circumferential surface, a top axial surface and a bottom axial surface.
In an aspect of the present disclosure, the thickness of the pocket at an end near the ring is less than the thickness of the pocket at an end near the pair of arms.
In another aspect of the present disclosure, axial openings are defined on the ring between the inner circumferential surface and an outer circumferential surface such that the pitch circle diameter of the axial openings coincides substantially with the pitch circle diameter of the pair of arms.
In another aspect of the present disclosure, the annular ring has chamfered edges.
In another aspect of the present disclosure, an outer surface of the plurality of projections tapers towards the pair of arms.
In yet another aspect of the present disclosure, the plurality of projections includes a plurality of inter-pocket protrusions. Each protrusion includes two branches defining the space and is connected to the ring, where the branches are connected by a rib located between the ring and the pair of arms.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING

A retainer cage for rolling elements of a bearing assembly of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a perspective view of a retainer cage for balls of the present disclosure, in accordance with an embodiment of the present disclosure;
Figures 2a to 2e illustrate different cut out portions of a profile of the retainer cage of Figure 1;
Figures 3a to 3d, illustrate different cut-out portions of a bearing assembly accommodating the retainer cage in an assembled configuration, in accordance with an embodiment of the present disclosure; and
Figure 4 illustrates a graphical representation of deflections of a conventional retainer cage and the retainer cage of the present disclosure at high speeds using finite element analysis technique (FEA).
LIST OF REFERENCE NUMERALS
100 - Retainer cage for rolling elements
10 -Annular ring
12 - Inner circumferential surface
14 - Outer circumferential surface
16 - Axial projections
18 -Pair of arms
20 - Space
22 - Pocket
24 - Axial opening
26 - Outer surface

28 - Dimple
30 - Bottom axial surface
32 - Branches
34 - Rib
50 - Rolling element
200 - Outer ring
300 - Inner ring
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a," "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," "including," and "having," are open ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or

components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
Terms such as "inner," "outer," "beneath," "below," "lower," "above," "upper," and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
The present disclosure envisages a retainer cage for rolling element bearings. The retainer cage for rolling element bearings (herein after referred to as "retainer cage 100") will now be described with respect to Figure 1 through Figure 4. The retainer cage 100 of the present disclosure enhances life and mechanical properties of rolling elements.
Referring to Figure 1, the retainer cage 100 for rolling element bearings of a bearing assembly is shown. The retainer cage 100 comprises an annular ring 10, a plurality of projections 16, and a pocket 22.
The annular ring 10 is defined by an inner circumferential surface 12, an outer circumferential surface 14, a flat top axial surface (not shown in figures) and a bottom axial surface 30, the top axial surface having chamfered edges.
The plurality of projections 16 is extending from the annular ring 10 axially. Each of the projections 16 is having a pair of arms 18 at its tip. Each of the pair of arms 18 defines a space 20 with adjacent pair of arms 18. The space 20 is configured to receive a rolling element 50, such that the pair of arms 18 and the adjacent pair of arms 18 hold the rolling element 50 within the space 20.
Each of the projections 16 of the retainer cage 100 has a plurality of pockets 22 at equal angular distance from each other. Further, an inner surface of the projections 16 defines the pocket 22 such that the depth of each of the pocket 22 at an end near the ring 10 is less than the depth of the pocket 22 at an end near the pair of arms 18. Each of the pockets 22 is adapted to retain a lubricant therein such that during operative conditions, the lubricant enters each pocket 22 through one or more axial openings 24. Each axial opening 24, is provided at the end near

the ring 10 for the lubricant to enter and exit the retainer cage 100 while operating or at rest conditions of the bearing assembly. The lubricant may preferably be grease. The retained lubricant travels from the pockets 22 over the bottom axial surface 30 and gets introduced in the space 20 where the rolling elements 50 are held, thereby facilitating lubrication of the rolling elements 50. Further, material is removed from the inner surface of the axial projection 16 during process of manufacture of each pocket 22, reducing the overall weight of the retainer cage 100, thereby reducing deflection of bearing assemblies at higher speeds preventing centrifugal effect.
In another embodiment, the axial openings 24 substantially lies between the inner circumferential surface 12 and the outer circumferential surface 14 of the ring 10. In an embodiment, the diameter of the axial openings 24 coincides substantially with a pitch circle of the pair of arms 18.
In an embodiment, a dimple 28 is defined on the bottom axial surface 30 in a manner such that the dimple 28 curves along a curve of the space 20. The dimple 28 facilitates seepage of the lubricant into the space 20 and also lends support to the rolling elements 50 held in the respective spaces 20 during high speed rotation. Such a construction of the retainer cage 100 minimizes deflection of the rolling elements 50 and keeps them well lubricated, thus avoiding friction and facilitating an unhindered movement of the roller element 50.
Referring to Figures 2a to 2e, different cut-out portions of a profile of the retainer cage 100 of the present disclosure are shown. As shown, the projections 16 includes a plurality of inter-pocket protrusions, each protrusion including two branches 32 which define the space 20 and are connected to the ring 10 in a manner that the branches 32 are connected by a rib 34 located between the ring 10 and the pair of arms 18. The rib 34 is provided at that end of the inner surface which is near the pair of arms 18. In another embodiment, the inner circumferential surface 12 perpendicular bearing rotating axis as shown in Fig. 2a

In another embodiment, an outer surface 26 of the projections 16 tapers from the ring 10 towards the arms 18, as shown in Fig. 2b. The tapering of the projections 16 reduces overall weight of the retainer cage 100 and facilitates lesser deflection of the retainer cage 100 and rolling elements 50 during high speed movement, thereby reducing the effect of the centrifugal forces acting during the high speed movement. In an embodiment, a small draft angle is provided at joining of the branches 32 and the bottom axial surface 30. The draft angle provided in the cross-section of the retainer cage 100 appreciates concentration of weight more towards center of the roller element bearing, further facilitating the stability of the rolling element bearing of the present disclosure.
Figure 2c shows a bottom view of the cut-out portion of the cross-section of the retainer cage 100 which depicts a thickness of the retainer cage 100 as outer circumferential surface 14 and the inner circumferential surface of the ring 10 are shown.
The dimple 28 that facilitates retaining of the lubricant and support for the rolling elements 50 held in the spaces 20 is shown in Figure 2d. Also, shown in Figure 2d is the axial opening 24 that facilitates entry of the lubricant into the pocket 22 for retaining and supplying the lubricant during high speed movement.
A detailed view of the upper surface 30 having the dimple 28 is shown in Figure 2e.
Referring to Figures 3a to 3d, different cut out portions depicting the retainer cage 100 sand witched between an inner ring 200 and an outer ring 300 of the bearing assembly of the present disclosure are shown. The outer surface 26 tapering from the bottom of the ring 10 towards the arms 18 is shown, that facilitates reduces deformation of the retainer cage 100 under the effect of the centrifugal forces.
In a working example, a conventional retainer and a retainer sample prepared in accordance with embodiments of the present disclosure were subjected to Finite

element analysis (FEA) technique for determining deflection or stress and strain during high speed movement. The results obtained are represented in Figure 4 via a graph. The graph represents two lines i.e. 300A and 300B to determine the deflection. It is observed from the graph that at less than 2000 RPM the deflection (> 50 microns) of both the retainer cages is almost similar. However, as the speed increases beyond 2000 RPM the deflection (400 microns) of the conventional retainer cage increases rapidly, whereas the retainer cage 100 of the present disclosure has comparatively less deflection (200 microns) even at higher speeds for example 8000 RPM as illustrated in graph. Thus, it can be concluded that the conventional retainer may deform beyond 8000 RPM speed due to higher centrifugal forces, while the retainer cage 100 of the present disclosure will hold its own even beyond 8000 RPM speed due to light weight of the retainer cage 100 and lesser amount of centrifugal forces acting over it.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a retainer cage for rolling elements of a bearing assembly, that:
• facilitates reduced deflection of rolling element bearings at higher speeds;
• enhances lubrication of balls;
• has reduced weight preventing centrifugal effect;
• enhances stability of bearing assemblies at higher speeds; and
• increases operational speed limit of bearing assemblies.

The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers, but not the exclusion of any other element, integer, or group of elements, integers.
The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

WE CLAIM:

1.A retainer cage (100) for rolling elements (50) of a bearing assembly, said
retainer cage (100) comprising:
a. an annular ring (10);
b. a plurality of axial projections (16) extending from said ring (10)
axially, each of said axial projections (10) having a pair of arms (18)
configured at tip of each of said axial projections (16);
c. a space (20) configured between two adjacent pair of arms (18) for
receiving a bearing element (50) therein; and
d. a pocket (22) defined in an inner surface of each of said axial
projections (16) configured to store a lubricant therein and to facilitate
lubrication to said bearing elements (50), said cage (100) configured to
reduce deflection and deformation of said bearing assemblies at higher
speeds.
2. The retainer cage (100) as claimed in claim 1, wherein the depth of each of said pockets (22) at an end near said ring (10) is less than the depth of each of said pockets (22) at an end near said pair of arms (18).
3. The retainer cage (100) as claimed in claim 1, wherein said ring (10) is defined by an inner circumferential surface (12), an outer circumferential surface (14), a top axial surface and a bottom axial surface (30).
4. The retainer cage (100) as claimed in claim 3, wherein a plurality of axial openings (24) is defined on said ring (10) between said inner circumferential surface (12) and said outer circumferential surface (14), wherein a pitch circle diameter of each of said axial openings (24) coincide substantially with a pitch circle diameter of said pair of arms (18).

5. The retainer cage (100) as claimed in claim 1, wherein said annular ring (10) has chamfered edges.
6. The retainer (100) as claimed in claim 1, wherein an outer surface (26) of each of said axial projections (16) tapers towards said pair of arms (18).
7. The retainer cage (100) as claimed in claim 1, wherein each of said axial projections (16) include a plurality of inter-pocket protrusions, each protrusion includes two branches (32) defining said space (20) and connected to said ring (10), wherein said branches (32) are connected by a rib (34) located between said ring (10) and said pair of arms (18).