The present disclosure related to the field of bearings. More particularly, the present disclosure relates to the surface treatment of bearings.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
The expression "ASTM A370-15" used hereinafter in this specification refers to, but is not limited to, a standard testing method for mechanically testing steel products, as per American Society for Testing and Materials (ASTM).
The expression "ASTM G99-05" used hereinafter in this specification refers to, but is not limited to, a testing method for wear testing materials with a pin-on-disk apparatus, as per American Society for Testing and Materials (ASTM).
The expression "Tribological" used hereinafter in this specification refers to, but is not limited to, a science and engineering of interacting surfaces in a relative motion which includes the study and application of principles of friction, lubrication, and wear.
The expression "Tribometer" used hereinafter in this specification refers to, but is not limited to, an instrument that measures tribological quantities, such as coefficient of friction, friction force, and wear volume between two surfaces in contact.
The expression "Austenization" used hereinafter in this specification refers to, but is not limited to, a process of heating iron, iron base metal, or steel to a temperature at which the crystal structure changes from ferrite to austenite.
The expression "Martensitic" used hereinafter in this specification refers to, but is not limited to, a very hard constituent of steel that is formed by quenching of austenite which traps carbon atoms that do not have time to diffuse out of the crystal structure.

BACKGROUND
Typically, in the automotive industry, bearings are designed so as to facilitate better fuel efficiency. The reduction in fuel consumption is achieved by designing bearing components that have reduced section thickness, reduced weight, and that are compact. Further, the reduction in the section thickness of the bearing components allows the bearing to operate in severe conditions that generate higher contact stresses.
Conventionally, bearings are subjected to surface treatment for altering and/or improving their strength and wear resistance according to the application requirements.
Typically, bearings are made of either through-hardened high carbon low alloyed steels or case-hardened low-carbon low alloyed steels, depending upon the performance required under designated lubricating environment.
Conventionally, while performing surface treatment, the bearing components are exposed to a large amount of heat, for prolonged time period, to achieve desired uniform phase transformation. Further, various quenching media are used during the quenching process to enhance different desired microstructure to obtain the required properties of the bearing.
The conventional surface treatment techniques/systems require a large setup for heating and then quenching the bearing along with a post treatment setup to obtain the desired properties of the bearing, thereby making the entire process expensive and time consuming. For example, in an induction hardening process, quenching process is required to be followed subsequent to induction hardening process to achieve desired property of the bearing. Additionally, during quenching process, the quenching media needs to be maintained at an appropriate temperature to achieve target properties.

Further, the conventional techniques/systems also fails to obtain the desired mechanical and/or tribological properties of the bearings due to abrupt/improper heating, thereby reducing the life of the bearings.
Therefore, there is felt a need of a system for treating a surface of bearing components and a process thereof that alleviates the above mentioned drawbacks of the conventional surface treatment systems.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a system for treating a surface of bearing components, which increases the load carrying capacity of the bearings.
Another object of the present disclosure is to provide a system for treating a surface of bearing components, which improves the tribological properties of the bearings.
Yet another object of the present disclosure is to provide a system for treating a surface of bearing components, which increases the fatigue strength of the bearings.
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 system for treating a surface of bearing components. The system comprises a rotary unit, at least one attachment, and a laser source. The at least one attachment is detachably connected to the rotary unit, wherein the rotary unit is configured to rotate at least one attachment. Further, the at least one attachment is configured to securely hold at least one of an inner ring, an outer ring, and a rolling element of the bearing, i.e., the components of the bearing.

The laser source is configured to generate a laser beam, and is further configured to focus the generated laser beam on the surface of at least one of the inner ring, the outer ring, and the rolling elements to perform surface treatment.
In another embodiment, an optical unit includes at least one collimating lens, at least one homogenized lens, a focusing lens, a protection lens or any combination thereof.
In embodiment, the system includes the optical unit that is configured to receive the laser beam generated by the laser source, and is further configured to transform the laser beam into a profiled laser beam. Further, the optical unit is configured to focus the profiled laser beam on the surface of at least one of inner ring, outer ring, and rolling elements, thereby performing surface treatment. In an embodiment, the shape of the profiled laser beam is selected from the group consisting of a square, a rectangle, a triangle, a circle, a trapezoid, and any geometrical or non-geometrical shape.
In an embodiment, the system includes a plurality of optical fibers configured to receive the laser beam from the laser source, and is further configured to carry and transmit the laser beam towards the optical unit.
Further, the optical unit comprises at least one collimating lens, at least one homogenized lens, and the focusing lens. The at least one collimating lens is configured to receive the laser beam emitted by the laser source, and is further configured to collimate and direct the laser beam towards at least one homogenized lens. The at least one homogenized lens is configured to receive and transform the collimated laser beam into a profiled laser beam. Further, the profiled laser beam is directed towards the focusing lens. The focusing lens, upon receiving the profiled laser beam, is configured to focus the profiled laser beam on at least one of the inner ring, the outer ring, and the rolling element.
In one embodiment, the optical unit includes the protection lens. The protection lens is disposed at a distal end of the optical unit. The protection lens is configured to prevent the entrance of any foreign particle within the optical unit.

In an embodiment, the system includes a first conduit and a second conduit, wherein the first conduit and second conduit are configured to supply shielding gas and air respectively on the surface of the bearing. The supply of shielding gas prevents spattering and the supply of air facilitates heat dissipation during the surface treatment 5 of the bearing components.
In an embodiment, the system includes a robotic arm. The robotic arm is configured to hold the optical unit, and is further configured to guide the optical unit towards at least one of the inner ring, the outer ring and the rolling element. In another embodiment, the robotic arm is configured to guide the optical unit to facilitate focusing of the 10 profiled laser beam on at least one of an outer surface of inner ring, an inner surface of outer ring, and the surface of the rolling element.
The present disclosure further envisages a process for treating a surface of bearing components. The process comprises the following steps:
• generating a laser beam by a laser source; and
15 • focusing, the generated laser beam on the surface of at least one of an inner
ring, an outer ring, and a rolling element, thereby performing surface treatment.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
A system for treating a surface of bearing components and a process thereof, of the present disclosure will now be described with the help of the accompanying drawing, 20 in which:
Figure 1 illustrates a schematic view of a system for treating a surface of bearing components, in accordance with an embodiment of the present disclosure;
Figure 2 illustrates a schematic view of an optical unit of the system of Figure 1;
6

Figure 3 illustrates an isometric view and a cross-sectional view of an attachment for an inner ring of the bearing, in accordance with an embodiment of the present disclosure;
Figure 4 illustrates a cross-sectional view of an attachment for an outer ring of the
5 bearing, in accordance with another embodiment of the present disclosure;
Figure 5 illustrates an isometric view and a cross-sectional view of an attachment for a roller element of the bearing, in accordance with still another embodiment of the present disclosure;
Figure 6 illustrates a flowchart depicting a process for treating a surface of bearing
10 components;
Figure 7A and 7B illustrates graphs depicting a comparative analysis of the performance parameter by using the system of Figure 1 and the conventional system respectively; and
Figure 8A and Figure 8B illustrates bar graphs depicting a comparative analysis of
15 the tribological parameters of the bearing being surface treated by using the system of
Figure 1 and the conventional system.
LIST OF REFERENCE NUMERALS USED IN DETAILED DESCRIPTION AND DRAWING

100 – System
102 – Laser source
104 – Optical unit
106 – Optical fiber
108 – First conduit
110 – Second conduit
7

112

–

At least one attachment

112a, 112b, 112c

-

Attachment

114 – Rotary unit
116 - Robotic arm
5 202 - At least one collimating lens
204 - At least one Homogenized lens
206 - Focusing lens
208 - Protection lens
302 - Lead screw
10 304 - Top cover
306 - Bottom cover
308 - Inner ring
402 - Bottom cover
404 - Middle cover
15 406 - Top cover
408 - Outer ring
410 - Gasket
502 - Holder assembly
504 - Body cover
20 506 - Cap
600 - Process
8

DETAILED DESCRIPTION
The present disclosure envisages a system for treating a surface of bearing components and a process thereof. The envisaged system and the process improve the load carrying capacity and tribological properties of the bearing being treated.
5 In a typical laser hardening process, a laser beam of specific power and spot size is
scanned on the bearing steel parts at a specific pre-determined speed. The laser
contact increases the surface temperature of steel surface to the extent of
austenitization temperature. Due to the fast movement of high intensity laser beam
along the surface, the local heat accumulated in the thin layer will quickly conduct
10 away, and the heated area cools rapidly, thereby inducing self-quenching effect, which
results in martensitic transformation to a depth, typically, ranging from 0.1 mm to 1.5 mm based on the requirements of the particular application.
The envisaged laser surface treatment, i.e., laser surface hardening (LSH) treatment, provides various advantages over the conventional surface hardening techniques such
15 as high degree of controllability, processing time, hardening of complex geometry
with precision, excellent amenability to automation, high processing speed, and the like. Further, the laser surface hardening provides various advantages over economical aspects including high throughput, reproducibility, and product quality. Furthermore, the primary advantage of LSH is to exhibit higher hardness than the conventional
20 surface hardening techniques which results in improvement of wear resistance. Also
the adhesive wear of the bearing can also be influenced by means of a reduction in the coefficient of friction. In addition, laser surface hardening improves the fatigue characteristics of treated surfaces by inducing higher compressive residual stresses, which exhibits high load carrying capacity to a level higher than the conventionally
25 surface hardened components.
An object of the present disclosure is to increase the load carrying capacity of the bearing which is achieved by laser hardening. The laser beam is scanned across an outer surface of an inner ring, an inner surface of an outer ring, and the surface of
9

rolling elements, of the bearing, to impart high hardness compared to the conventional hardening techniques. The envisaged system and the process of the present disclosure improve the load carrying capacity of the bearing without the addition of any alloying elements which results in size reduction of the bearing.
5 A preferred embodiment of a system 100 for treating a surface of bearing components,
of the present disclosure, is now being described in detail with reference to Figure 1
through Figure 8B. The surface treatment is performed on the outer surface of an
inner ring 308, inner surface of an outer ring 408, and on the surface of the rolling
elements, of the bearing. Referring to figures, the system 100 comprises a laser source
10 102, a rotary unit 114, and at least one attachment 112.
The rotary unit 114 includes a rotary table (not exclusively labelled in the figures), a chuck (not shown in the figures), and a drive motor (not shown in the figures) wherein the drive motor is coupled to the rotary table to provide rotary drive to the rotary table. Further, the chuck is mounted on the rotary table by means of a plurality of
15 fasteners. In an embodiment, the chuck is configured to securely hold the at least one
attachment 112 by means of plurality of fasteners. In an embodiment, the at least one attachment 112 is detachably connected to the rotary unit 114, specifically, the at least one attachment 112 is mounted on the chuck of the rotary unit 114. In an embodiment, the chuck is selected from the group consisting of self-centering chuck, independent
20 chuck, magnetic chuck, electrostatic chuck, vacuum chuck, collets, drill chucks or any
holding device. Further, the drive motor is configured to rotate the rotary table of the rotary unit 114, thereby rotating the chuck and the at least one attachment 112 mounted on the rotary table.
In an embodiment, the at least one attachment 112 is detachably connected by means
25 of a plurality of fasteners. In another embodiment, the at least one attachment 112 is
detachably connected to the rotary table by means of snap fits.
10

The at least one attachment 112 is configured to securely hold the components, i.e., at least one of the inner ring 308, the outer ring 408, and a rolling element, of the bearing (not shown in figures).
The laser source 102 is configured to generate a laser beam of a specific wavelength,
5 wherein the generated laser beam is focused on the surface of at least one of the inner
ring 308, the outer ring 408, and the rolling elements to perform surface treatment. In
an embodiment, the laser source 102 is configured to provide a tailored laser beam
having a pre-defined profile which is complementary to the surface of the bearing
components, i.e., at least one of inner ring 308, outer ring 408 and rolling elements
10 being subjected to the surface treatment.
In an embodiment, the laser source 102 may include a beam conversion unit (not
shown in figures). The beam conversion unit may be configured to convert the
generated laser beam in to the tailored laser beam having pre-defined profile, wherein
the profile of the tailored laser beam is complementary to the surface of the bearing
15 components.
In another aspect of the present disclosure, the system 100 includes an optical unit
104. The optical unit 104 is configured to receive the laser beam from the laser source
102 by means of a plurality of optical fibers 106. The plurality of optical fibers 106 is
configured to receive the laser beam from the laser source 102, and is further
20 configured to transmit the laser beam towards the optical unit 104. In an embodiment,
the laser beam fed to the optical unit 104 by the plurality of optical fibers 106 is a divergent laser beam.
In an embodiment, the optical unit 104 includes at least one collimating lens 202, at
least one homogenized lens 204, a focusing lens 206, a protection lens 208, or any
25 combination thereof. In another embodiment, the at least one collimating lens 202, the
at least one homogenized lens 204, the focusing lens 206, and the protection lens 208 are arranged sequentially.
11

Further, the optical unit 104 is configured to receive the laser beam, and is further configured to transform the laser beam into a profiled laser beam. The optical unit 104 is configured to focus the profiled laser beam on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling element, thereby treating the surface of 5 the bearing components. Typically, the surface treatment is performed on:
• an outer surface of the inner ring 308;
• an inner surface of the outer ring 408; and
• the surface of the rolling element.
In an embodiment, the treatment performed on the surface of the bearing components 10 is a laser surface hardening treatment.
In another embodiment, the shape of the profiled laser beam is selected from the group consisting of a square, a rectangle, a triangle, a circle, a trapezoid, and any geometrical or non-geometrical shape.
The at least one collimating lens 202 is configured to receive the laser beam emitted
15 by the laser source 102, by means of the plurality of optical fibers 106. Also, the at
least one collimating lens 202 is configured to collimate the laser beam, and is further
configured to direct the collimated laser beam towards the homogenized lens 204. The
at least one homogenized lens 204 is placed in a spaced apart manner from the at least
one collimating lens 202, and is configured to receive the collimated laser beam.
20 Further, the at least one homogenized lens 204 is configured to transform the
collimated laser beam into the profiled laser beam. Furthermore, the focusing lens 206
is placed in spaced apart manner from the at least one homogenized lens 204. The
focusing lens 206 is configured to receive the profiled laser beam, and is further
configured to focus the profiled laser beam on the surface of the bearing components
25 via the protection lens 208. The protection lens 208 is disposed at a distal end of the
optical unit 104. The protection lens 208 is configured to protect the at least one
collimating lens 202, the homogenized lens 204, and the focusing lens 206 placed
12

within the optical unit 104, by preventing the entrance of any foreign particles within the optical unit 104.
The system 100 includes a first conduit 108 and a second conduit 110. The first
conduit 108 is configured to supply a shielding gas on the surface of at least one of the
5 inner ring 308, the outer ring 408, and the rolling element of the bearing, thereby
preventing spattering during the surface treatment. The second conduit 110 is configured to supply air on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling element of the bearing, thereby facilitating dissipation of the heat generated during the surface treatment.
10 In an embodiment, the shielding gas is an inert gas, i.e., argon gas. Typically, the
surface being treated gets heated rapidly due to the projection of the laser beam on the surface which may lead to oxidization of the surface of the bearing. Further, the probability of oxidization is reduced by supplying the shielding gas and air on the surface of the bearing components during the surface treatment.
15 The system 100 further includes a robotic arm 116. The robotic arm 116 is configured
to hold the optical unit 104. In an embodiment, the robotic arm 116 is a six-axis robot which allows the optical unit 104 to travel through X-Y-Z axes and turn around X-Y-Z axis. Further, the robotic arm 116 is configured to guide the optical unit 104 towards the at least one of the outer ring 408, the inner ring 308, and the rolling
20 element of the bearing. Furthermore, the robotic arm is configured to guide the optical
unit such that the profiled laser beam is scanned and focused over the outer surface of inner bearing, inner surface of outer bearing and on the surface of rolling element of the bearing using the robotic arm 116. In an embodiment, the movement of the robotic arm 116 is controlled by means of a robotic controller (not shown in figures).
25 In an embodiment, the profiled laser beam with pre-determined laser power is scanned
on the surface of the at least one of inner ring 308, the outer ring 408, and the rolling element of the bearing at a pre-determined scanning speed. In another embodiment,
13

the pre-determined scanning speed is selected so as to harden the surface layer at the interaction region to a depth of few hundreds of micrometer.
Referring to Figure 3, when the outer surface of an inner ring 308 of the bearing is to
be surface treated, an attachment 112a is detachably connected to the rotary unit 114.
5 The attachment 112a is configured to securely hold the inner ring 308 of the bearing
thereon. The attachment 112a comprises a lead screw 302, a top cover 304, a bottom cover 306, and the inner ring 308. In an embodiment, the lead screw 302 is circumscribed by the bottom cover 306 at a lower operative end of the lead screw 302. Further, the inner ring 308 is mounted on the top of the bottom cover 306
10 circumscribing the lead screw 302. Further, the top cover 304 is mounted on top of the
inner ring 308 circumscribing the middle portion of the lead screw 302. Further, the arrangement of the top cover 304, the inner ring 308, and the bottom cover 306 is secured by fastening a nut (not shown in figures) to free end of the lead screw 302. Furthermore, a circumferential clearance is provided between the top cover 304, the
15 bottom cover 306, and the inner ring 308 with respect to the surface of the lead screw
302. In an embodiment, an orifice in configured on the top cover 304 to supply fluid (water/ heat dissipating fluid) to the inner surface of the inner ring 308 which facilities efficient heat dissipation during the surface treatment of the outer surface of the inner ring 308. In an embodiment, a washer (not shown in figures) is arranged between the
20 top cover 304 and the nut (not shown in figures) to prevent fluid leakage. The
attachment 112a for the inner ring 308 is connected to the rotary unit 114 which rotates the attachment at a pre-determined speed and simultaneously the outer surface of the inner ring 308 is exposed to the profiled laser beam. In an embodiment, the shape of the profiled laser beam is complementary to the profile of the outer surface of
25 the inner ring 308, thereby providing appropriate surface hardening.
Referring to Figure 4, another attachment 112b is detachably connected to the rotary
unit 114, wherein the attachment 112b is configured to hold the outer ring 408 of the
bearing for the surface treatment. The attachment 112b comprises of a bottom cover
402, a top cover 406, and a middle cover 404 having a hollow cylindrical structure.
30 The outer ring 408 of the bearing is encapsulated between the top cover 406 and
14

middle cover 404, wherein the top cover 406 and middle cover 404 are fastened by
bolt and nut assembly. In an embodiment the outer surface of the outer ring 408 is
surrounded with the fluid (water/ heat dissipating fluid) to facilitate heat dissipation
during the surface treatment of the outer ring 408. Further, a gasket 410 is disposed
5 between the top cover 406 and the middle cover 404 to prevent any leakage of the
fluid from the attachment 112b. The assembly of the top cover 406 and the middle
cover 404 are fixed to the bottom cover 402 by fastening means. Further, the
attachment 112b is detachably connected to the rotary unit which rotates the
attachment 112b at a pre-determined speed and simultaneously the inner surface of the
10 outer ring 408 is exposed to the profiled laser beam for surface treatment. In an
embodiment, the shape of the profiled laser beam is complementary to the profile of the inner surface of the outer ring 408.
Figure 5 illustrates still another attachment 112c that is configured to hold the roller element of the bearing. The attachment 112c comprises a holder assembly 502, a body
15 cover 504, and a cap 506. The holder assembly 502 is enclosed by the cylindrical
hollow body cover 504. Further, the holder assembly 502 is encapsulated between the cap 506 and the body cover 504, and is securely fastened by a bolt and nut assembly. In an embodiment, the holder assembly 502 is a magnetic assembly. Further, the holder assembly has an extended tapered tip. In an embodiment, the profile of the
20 extended tapered tip is complementary to the side face diameter of the roller element
providing easy alignment of the roller element with the holder assembly 502. In an operative configuration, when the surface of the roller element is to be surface treated, the attachment 112c is connected to the rotary unit 114 which rotates the attachment 112c at a pre-determined speed, against the laser being impinged on the surface of the
25 rolling element. In an embodiment the arrangement of the attachment is such that, the
central axis of the rolling element is aligned with the axis of the rotary unit 114 to provide uniform surface treatment of the rolling element. In an embodiment, the shape of the profiled laser beam being impinged on the rolling element is complimentary to the profile of the rolling element of the bearing.
15

As depicted in Figure 6, the present disclosure envisages a process 600 for treating the surface of the bearing components. The process 600 for treating the surface of the bearing components comprises the following steps:
At block 602, the process 600 includes the step of generating the laser beam by the
5 laser source 102.
At block 604, the process 600 includes the step of focusing the generated laser beam, by the laser source 102, on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling element, to perform surface treatment.
Figure 7A and Figure 7B illustrates graphs depicting a comparative analysis of the
10 performance parameter of the system 100 of the present disclosure and the
conventional system. An analysis was performed to evaluate the tensile strength of the
laser surface treatment with the conventional surface treatment. In an embodiment, the
bearing on which the laser surface treatment was carried out is a surface treated 3.0
mm thick flat SAE 52100 steel. Further, to evaluate the tensile strength of the laser
15 surface treated bearing and the conventional surface treated bearing, a room
temperature static tensile testing was carried out as per ASTM A370-15 standards
with laser surface treatment being carried out under optimum processing conditions.
Laser surface treated samples exhibited 1700 ± 30 MPa of tensile strength when
compared to that of conventionally surface treated and tempered samples whose
20 tensile strength is 1500 ± 50 MPa. The proposed laser surface treatment showed
maximum improvement in tensile strength, i.e., by 25% due to the combination of
residual stress.
Figure 8A and Figure 8B illustrates bar graphs depicting a comparative analysis of
the tribological parameters of the laser surface treated sample with the conventional
25 surface treated sample. The comparative sliding wear behavior was evaluated in terms
of wear rate and the co-efficient of friction. The reported wear rate test was carried out as per ASTM G99-05 by employing ball-on-disc tribometer under 4.17GPa Hertzian contact pressures in both lubricated and dry conditions. The wear depth was
16

substantially reduced in the laser surface treated sample compared to that of the
conventional surface treated sample. A furthermore advantage of the invention is
reduction in friction co-efficient i.e. 0.55 in dry condition and 0.075 in lubricated
condition, due to Laser surface treatment as compared to the conventional surface
5 treatment, whose values are 0.6 in dry and 0.1 in lubricated conditions. On the whole,
the tribological improvement in the laser surface treatment could be attributed to hard refined martensitic transformation microstructure with modified carbide morphologies.
Thus, the results presented indicates vast improvement in various
10 mechanical/tribological properties of laser surface treated bearing compared to
conventionally surface treated bearing under optimum laser processing conditions and setups.
The envisaged system 100 and the process 600 results in martensitic with extremely fine carbides structures leading to higher hardness as compared to conventional
15 surface hardening techniques like case-hardening or induction hardening on account
of high cooling rates associated with localized process. The macro stresses that laser hardened surface generate is of high compressive nature. This happens due to formation of highly stressed martensite depending on the processing conditions and metallurgy of steel. The laser surface treatment of the bearing, of the present
20 disclosure, facilitates in producing higher surface hardness, as high as 1000 HV.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a system for treating a surface of 25 bearing components and a process thereof, that:
• increases the load carrying capacity of the bearings;
• improves the tribological properties of the bearings; and
17

• increases the fatigue strength of the bearings.
The disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
5 The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the 10 embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge,
15 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
20 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” 25 or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
18

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.
Any discussion of documents, acts, materials, devices, articles or the like that has
5 been included in this specification is solely for the purpose of providing a context for
the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
10 The numerical values mentioned for the various physical parameters, dimensions or
quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
15 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
20 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.

Claims:WE CLAIM

1.A system for treating a surface of bearing components, said system (100) comprising:
at least one attachment (112) configured to securely hold at least one of an inner ring (308), an outer ring (408), and a rolling element of said bearing;
a rotary unit (116) detachably connected to said at least one attachment (112), said rotary unit (116) configured to rotate said at least one attachment; and
a laser source (102) configured to generate a laser beam and is further configured to focus said generated laser beam on the surface of at least one of said inner ring (308), said outer ring (408), and said rolling elements to perform surface treatment.
2. The system (100) as claimed in claim 1, wherein said system (100) comprises an optical unit (104) configured to receive said laser beam from said laser source (102) to transform said laser beam into a profiled laser beam, and is further configured to focus said profiled laser beam on the surface of at least one of said inner ring (308), said outer ring (408), and said rolling elements to perform surface treatment.
3. The system (100) as claimed in claim 2, wherein said optical unit (104) includes at least one collimating lens (202), at least one homogenized lens (204), a focusing lens (206), a protection lens (208) or any combination thereof.

4. The system (100) as claimed in claim 3, wherein said optical unit (104) comprises:
said at least one collimating lens (202) configured to receive said laser beam by said laser source (102), and further configured to collimate and direct said received laser beam;
said at least one homogenized lens (204) configured to receive said collimated laser beam from said collimating lens (202), and further configured to transform said collimated laser beam to said profiled laser beam; and
said focusing lens (206) configured to receive said profiled laser beam from said homogenized lens (204), and further configured to focus said profiled laser beam on at least one of said inner ring (308), said outer ring (408), and said rolling elements.
said protection lens (208) is disposed at a distal end of said optical unit (104), and is configured to prevent the entrance of any foreign particle within said optical unit (104).
5. The system (100) as claimed in claim 1, which includes a first conduit (108) and a second conduit (110), wherein said first conduit (108) and said second conduit (110) are configured to supply shielding gas and air respectively on the surface of said bearing, thereby preventing spattering and facilitating heat dissipation during the surface treatment of said bearing.
6. The system (100) as claimed in claim 1, which includes a plurality of optical fibers (106) configured to receive said laser beam from said laser source (102), and further configured to carry and transmit said laser beam towards said optical unit (104).
7. The system (100) as claimed in claim 1, which includes a robotic arm (116) configured to hold said optical unit (104), and further configured to guide said optical unit (104) towards at least one of said outer ring (408), said inner ring (308), and said rolling element.
8. The system (100) as claimed in claim 7, wherein said robotic arm (116) is configured to guide said optical unit (104) to facilitate focusing of said profiled laser beam on at least one of an outer surface of said inner ring (308), an inner surface of said outer ring (408), and surface of said rolling element.
9. The system (100) as claimed in claim 1, wherein the shape of said profiled laser beam is selected from the group consisting of a square, a rectangle, a triangle, a circle, a trapezoid, and any geometrical or non-geometrical shape.
10. A process for treating a surface of bearing components, said process (600) comprising the following steps:
• generating a laser beam by a laser source (102); and
• focusing said generated laser beam on the surface of at least one of an inner ring (308), an outer ring (408), and a rolling element to perform surface treatment.
, Description:FIELD
The present disclosure related to the field of bearings. More particularly, the present disclosure relates to the surface treatment of bearings.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
The expression “ASTM A370-15” used hereinafter in this specification refers to, but is not limited to, a standard testing method for mechanically testing steel products, as per American Society for Testing and Materials (ASTM).
The expression “ASTM G99-05” used hereinafter in this specification refers to, but is not limited to, a testing method for wear testing materials with a pin-on-disk apparatus, as per American Society for Testing and Materials (ASTM).
The expression “Tribological” used hereinafter in this specification refers to, but is not limited to, a science and engineering of interacting surfaces in a relative motion which includes the study and application of principles of friction, lubrication, and wear.
The expression “Tribometer” used hereinafter in this specification refers to, but is not limited to, an instrument that measures tribological quantities, such as coefficient of friction, friction force, and wear volume between two surfaces in contact.
The expression “Austenization” used hereinafter in this specification refers to, but is not limited to, a process of heating iron, iron base metal, or steel to a temperature at which the crystal structure changes from ferrite to austenite.
The expression “Martensitic” used hereinafter in this specification refers to, but is not limited to, a very hard constituent of steel that is formed by quenching of austenite which traps carbon atoms that do not have time to diffuse out of the crystal structure.
BACKGROUND
Typically, in the automotive industry, bearings are designed so as to facilitate better fuel efficiency. The reduction in fuel consumption is achieved by designing bearing components that have reduced section thickness, reduced weight, and that are compact. Further, the reduction in the section thickness of the bearing components allows the bearing to operate in severe conditions that generate higher contact stresses.
Conventionally, bearings are subjected to surface treatment for altering and/or improving their strength and wear resistance according to the application requirements.
Typically, bearings are made of either through-hardened high carbon low alloyed steels or case-hardened low-carbon low alloyed steels, depending upon the performance required under designated lubricating environment.
Conventionally, while performing surface treatment, the bearing components are exposed to a large amount of heat, for prolonged time period, to achieve desired uniform phase transformation. Further, various quenching media are used during the quenching process to enhance different desired microstructure to obtain the required properties of the bearing.
The conventional surface treatment techniques/systems require a large setup for heating and then quenching the bearing along with a post treatment setup to obtain the desired properties of the bearing, thereby making the entire process expensive and time consuming. For example, in an induction hardening process, quenching process is required to be followed subsequent to induction hardening process to achieve desired property of the bearing. Additionally, during quenching process, the quenching media needs to be maintained at an appropriate temperature to achieve target properties.
Further, the conventional techniques/systems also fails to obtain the desired mechanical and/or tribological properties of the bearings due to abrupt/improper heating, thereby reducing the life of the bearings.
Therefore, there is felt a need of a system for treating a surface of bearing components and a process thereof that alleviates the above mentioned drawbacks of the conventional surface treatment systems.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a system for treating a surface of bearing components, which increases the load carrying capacity of the bearings.
Another object of the present disclosure is to provide a system for treating a surface of bearing components, which improves the tribological properties of the bearings.
Yet another object of the present disclosure is to provide a system for treating a surface of bearing components, which increases the fatigue strength of the bearings.
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 system for treating a surface of bearing components. The system comprises a rotary unit, at least one attachment, and a laser source. The at least one attachment is detachably connected to the rotary unit, wherein the rotary unit is configured to rotate at least one attachment. Further, the at least one attachment is configured to securely hold at least one of an inner ring, an outer ring, and a rolling element of the bearing, i.e., the components of the bearing.
The laser source is configured to generate a laser beam, and is further configured to focus the generated laser beam on the surface of at least one of the inner ring, the outer ring, and the rolling elements to perform surface treatment.
In another embodiment, an optical unit includes at least one collimating lens, at least one homogenized lens, a focusing lens, a protection lens or any combination thereof.
In embodiment, the system includes the optical unit that is configured to receive the laser beam generated by the laser source, and is further configured to transform the laser beam into a profiled laser beam. Further, the optical unit is configured to focus the profiled laser beam on the surface of at least one of inner ring, outer ring, and rolling elements, thereby performing surface treatment. In an embodiment, the shape of the profiled laser beam is selected from the group consisting of a square, a rectangle, a triangle, a circle, a trapezoid, and any geometrical or non-geometrical shape.
In an embodiment, the system includes a plurality of optical fibers configured to receive the laser beam from the laser source, and is further configured to carry and transmit the laser beam towards the optical unit.
Further, the optical unit comprises at least one collimating lens, at least one homogenized lens, and the focusing lens. The at least one collimating lens is configured to receive the laser beam emitted by the laser source, and is further configured to collimate and direct the laser beam towards at least one homogenized lens. The at least one homogenized lens is configured to receive and transform the collimated laser beam into a profiled laser beam. Further, the profiled laser beam is directed towards the focusing lens. The focusing lens, upon receiving the profiled laser beam, is configured to focus the profiled laser beam on at least one of the inner ring, the outer ring, and the rolling element.
In one embodiment, the optical unit includes the protection lens. The protection lens is disposed at a distal end of the optical unit. The protection lens is configured to prevent the entrance of any foreign particle within the optical unit.
In an embodiment, the system includes a first conduit and a second conduit, wherein the first conduit and second conduit are configured to supply shielding gas and air respectively on the surface of the bearing. The supply of shielding gas prevents spattering and the supply of air facilitates heat dissipation during the surface treatment of the bearing components.
In an embodiment, the system includes a robotic arm. The robotic arm is configured to hold the optical unit, and is further configured to guide the optical unit towards at least one of the inner ring, the outer ring and the rolling element. In another embodiment, the robotic arm is configured to guide the optical unit to facilitate focusing of the profiled laser beam on at least one of an outer surface of inner ring, an inner surface of outer ring, and the surface of the rolling element.
The present disclosure further envisages a process for treating a surface of bearing components. The process comprises the following steps:
• generating a laser beam by a laser source; and
• focusing, the generated laser beam on the surface of at least one of an inner ring, an outer ring, and a rolling element, thereby performing surface treatment.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
A system for treating a surface of bearing components and a process thereof, of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a schematic view of a system for treating a surface of bearing components, in accordance with an embodiment of the present disclosure;
Figure 2 illustrates a schematic view of an optical unit of the system of Figure 1;
Figure 3 illustrates an isometric view and a cross-sectional view of an attachment for an inner ring of the bearing, in accordance with an embodiment of the present disclosure;
Figure 4 illustrates a cross-sectional view of an attachment for an outer ring of the bearing, in accordance with another embodiment of the present disclosure;
Figure 5 illustrates an isometric view and a cross-sectional view of an attachment for a roller element of the bearing, in accordance with still another embodiment of the present disclosure;
Figure 6 illustrates a flowchart depicting a process for treating a surface of bearing components;
Figure 7A and 7B illustrates graphs depicting a comparative analysis of the performance parameter by using the system of Figure 1 and the conventional system respectively; and
Figure 8A and Figure 8B illustrates bar graphs depicting a comparative analysis of the tribological parameters of the bearing being surface treated by using the system of Figure 1 and the conventional system.
LIST OF REFERENCE NUMERALS USED IN DETAILED DESCRIPTION AND DRAWING
100 – System
102 – Laser source
104 – Optical unit
106 – Optical fiber
108 – First conduit
110 – Second conduit
112 – At least one attachment
112a, 112b, 112c - Attachment
114 – Rotary unit
116 - Robotic arm
202 - At least one collimating lens
204 - At least one Homogenized lens
206 - Focusing lens
208 - Protection lens
302 - Lead screw
304 - Top cover
306 - Bottom cover
308 - Inner ring
402 - Bottom cover
404 - Middle cover
406 - Top cover
408 - Outer ring
410 - Gasket
502 - Holder assembly
504 - Body cover
506 - Cap
600 - Process
DETAILED DESCRIPTION
The present disclosure envisages a system for treating a surface of bearing components and a process thereof. The envisaged system and the process improve the load carrying capacity and tribological properties of the bearing being treated.
In a typical laser hardening process, a laser beam of specific power and spot size is scanned on the bearing steel parts at a specific pre-determined speed. The laser contact increases the surface temperature of steel surface to the extent of austenitization temperature. Due to the fast movement of high intensity laser beam along the surface, the local heat accumulated in the thin layer will quickly conduct away, and the heated area cools rapidly, thereby inducing self-quenching effect, which results in martensitic transformation to a depth, typically, ranging from 0.1 mm to 1.5 mm based on the requirements of the particular application.
The envisaged laser surface treatment, i.e., laser surface hardening (LSH) treatment, provides various advantages over the conventional surface hardening techniques such as high degree of controllability, processing time, hardening of complex geometry with precision, excellent amenability to automation, high processing speed, and the like. Further, the laser surface hardening provides various advantages over economical aspects including high throughput, reproducibility, and product quality. Furthermore, the primary advantage of LSH is to exhibit higher hardness than the conventional surface hardening techniques which results in improvement of wear resistance. Also the adhesive wear of the bearing can also be influenced by means of a reduction in the coefficient of friction. In addition, laser surface hardening improves the fatigue characteristics of treated surfaces by inducing higher compressive residual stresses, which exhibits high load carrying capacity to a level higher than the conventionally surface hardened components.
An object of the present disclosure is to increase the load carrying capacity of the bearing which is achieved by laser hardening. The laser beam is scanned across an outer surface of an inner ring, an inner surface of an outer ring, and the surface of rolling elements, of the bearing, to impart high hardness compared to the conventional hardening techniques. The envisaged system and the process of the present disclosure improve the load carrying capacity of the bearing without the addition of any alloying elements which results in size reduction of the bearing.
A preferred embodiment of a system 100 for treating a surface of bearing components, of the present disclosure, is now being described in detail with reference to Figure 1 through Figure 8B. The surface treatment is performed on the outer surface of an inner ring 308, inner surface of an outer ring 408, and on the surface of the rolling elements, of the bearing. Referring to figures, the system 100 comprises a laser source 102, a rotary unit 114, and at least one attachment 112.
The rotary unit 114 includes a rotary table (not exclusively labelled in the figures), a chuck (not shown in the figures), and a drive motor (not shown in the figures) wherein the drive motor is coupled to the rotary table to provide rotary drive to the rotary table. Further, the chuck is mounted on the rotary table by means of a plurality of fasteners. In an embodiment, the chuck is configured to securely hold the at least one attachment 112 by means of plurality of fasteners. In an embodiment, the at least one attachment 112 is detachably connected to the rotary unit 114, specifically, the at least one attachment 112 is mounted on the chuck of the rotary unit 114. In an embodiment, the chuck is selected from the group consisting of self-centering chuck, independent chuck, magnetic chuck, electrostatic chuck, vacuum chuck, collets, drill chucks or any holding device. Further, the drive motor is configured to rotate the rotary table of the rotary unit 114, thereby rotating the chuck and the at least one attachment 112 mounted on the rotary table.
In an embodiment, the at least one attachment 112 is detachably connected by means of a plurality of fasteners. In another embodiment, the at least one attachment 112 is detachably connected to the rotary table by means of snap fits.
The at least one attachment 112 is configured to securely hold the components, i.e., at least one of the inner ring 308, the outer ring 408, and a rolling element, of the bearing (not shown in figures).
The laser source 102 is configured to generate a laser beam of a specific wavelength, wherein the generated laser beam is focused on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling elements to perform surface treatment. In an embodiment, the laser source 102 is configured to provide a tailored laser beam having a pre-defined profile which is complementary to the surface of the bearing components, i.e., at least one of inner ring 308, outer ring 408 and rolling elements being subjected to the surface treatment.
In an embodiment, the laser source 102 may include a beam conversion unit (not shown in figures). The beam conversion unit may be configured to convert the generated laser beam in to the tailored laser beam having pre-defined profile, wherein the profile of the tailored laser beam is complementary to the surface of the bearing components.
In another aspect of the present disclosure, the system 100 includes an optical unit 104. The optical unit 104 is configured to receive the laser beam from the laser source 102 by means of a plurality of optical fibers 106. The plurality of optical fibers 106 is configured to receive the laser beam from the laser source 102, and is further configured to transmit the laser beam towards the optical unit 104. In an embodiment, the laser beam fed to the optical unit 104 by the plurality of optical fibers 106 is a divergent laser beam.
In an embodiment, the optical unit 104 includes at least one collimating lens 202, at least one homogenized lens 204, a focusing lens 206, a protection lens 208, or any combination thereof. In another embodiment, the at least one collimating lens 202, the at least one homogenized lens 204, the focusing lens 206, and the protection lens 208 are arranged sequentially.
Further, the optical unit 104 is configured to receive the laser beam, and is further configured to transform the laser beam into a profiled laser beam. The optical unit 104 is configured to focus the profiled laser beam on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling element, thereby treating the surface of the bearing components. Typically, the surface treatment is performed on:
• an outer surface of the inner ring 308;
• an inner surface of the outer ring 408; and
• the surface of the rolling element.
In an embodiment, the treatment performed on the surface of the bearing components is a laser surface hardening treatment.
In another embodiment, the shape of the profiled laser beam is selected from the group consisting of a square, a rectangle, a triangle, a circle, a trapezoid, and any geometrical or non-geometrical shape.
The at least one collimating lens 202 is configured to receive the laser beam emitted by the laser source 102, by means of the plurality of optical fibers 106. Also, the at least one collimating lens 202 is configured to collimate the laser beam, and is further configured to direct the collimated laser beam towards the homogenized lens 204. The at least one homogenized lens 204 is placed in a spaced apart manner from the at least one collimating lens 202, and is configured to receive the collimated laser beam. Further, the at least one homogenized lens 204 is configured to transform the collimated laser beam into the profiled laser beam. Furthermore, the focusing lens 206 is placed in spaced apart manner from the at least one homogenized lens 204. The focusing lens 206 is configured to receive the profiled laser beam, and is further configured to focus the profiled laser beam on the surface of the bearing components via the protection lens 208. The protection lens 208 is disposed at a distal end of the optical unit 104. The protection lens 208 is configured to protect the at least one collimating lens 202, the homogenized lens 204, and the focusing lens 206 placed within the optical unit 104, by preventing the entrance of any foreign particles within the optical unit 104.
The system 100 includes a first conduit 108 and a second conduit 110. The first conduit 108 is configured to supply a shielding gas on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling element of the bearing, thereby preventing spattering during the surface treatment. The second conduit 110 is configured to supply air on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling element of the bearing, thereby facilitating dissipation of the heat generated during the surface treatment.
In an embodiment, the shielding gas is an inert gas, i.e., argon gas. Typically, the surface being treated gets heated rapidly due to the projection of the laser beam on the surface which may lead to oxidization of the surface of the bearing. Further, the probability of oxidization is reduced by supplying the shielding gas and air on the surface of the bearing components during the surface treatment.
The system 100 further includes a robotic arm 116. The robotic arm 116 is configured to hold the optical unit 104. In an embodiment, the robotic arm 116 is a six-axis robot which allows the optical unit 104 to travel through X-Y-Z axes and turn around X-Y-Z axis. Further, the robotic arm 116 is configured to guide the optical unit 104 towards the at least one of the outer ring 408, the inner ring 308, and the rolling element of the bearing. Furthermore, the robotic arm is configured to guide the optical unit such that the profiled laser beam is scanned and focused over the outer surface of inner bearing, inner surface of outer bearing and on the surface of rolling element of the bearing using the robotic arm 116. In an embodiment, the movement of the robotic arm 116 is controlled by means of a robotic controller (not shown in figures).
In an embodiment, the profiled laser beam with pre-determined laser power is scanned on the surface of the at least one of inner ring 308, the outer ring 408, and the rolling element of the bearing at a pre-determined scanning speed. In another embodiment, the pre-determined scanning speed is selected so as to harden the surface layer at the interaction region to a depth of few hundreds of micrometer.
Referring to Figure 3, when the outer surface of an inner ring 308 of the bearing is to be surface treated, an attachment 112a is detachably connected to the rotary unit 114. The attachment 112a is configured to securely hold the inner ring 308 of the bearing thereon. The attachment 112a comprises a lead screw 302, a top cover 304, a bottom cover 306, and the inner ring 308. In an embodiment, the lead screw 302 is circumscribed by the bottom cover 306 at a lower operative end of the lead screw 302. Further, the inner ring 308 is mounted on the top of the bottom cover 306 circumscribing the lead screw 302. Further, the top cover 304 is mounted on top of the inner ring 308 circumscribing the middle portion of the lead screw 302. Further, the arrangement of the top cover 304, the inner ring 308, and the bottom cover 306 is secured by fastening a nut (not shown in figures) to free end of the lead screw 302. Furthermore, a circumferential clearance is provided between the top cover 304, the bottom cover 306, and the inner ring 308 with respect to the surface of the lead screw 302. In an embodiment, an orifice in configured on the top cover 304 to supply fluid (water/ heat dissipating fluid) to the inner surface of the inner ring 308 which facilities efficient heat dissipation during the surface treatment of the outer surface of the inner ring 308. In an embodiment, a washer (not shown in figures) is arranged between the top cover 304 and the nut (not shown in figures) to prevent fluid leakage. The attachment 112a for the inner ring 308 is connected to the rotary unit 114 which rotates the attachment at a pre-determined speed and simultaneously the outer surface of the inner ring 308 is exposed to the profiled laser beam. In an embodiment, the shape of the profiled laser beam is complementary to the profile of the outer surface of the inner ring 308, thereby providing appropriate surface hardening.
Referring to Figure 4, another attachment 112b is detachably connected to the rotary unit 114, wherein the attachment 112b is configured to hold the outer ring 408 of the bearing for the surface treatment. The attachment 112b comprises of a bottom cover 402, a top cover 406, and a middle cover 404 having a hollow cylindrical structure. The outer ring 408 of the bearing is encapsulated between the top cover 406 and middle cover 404, wherein the top cover 406 and middle cover 404 are fastened by bolt and nut assembly. In an embodiment the outer surface of the outer ring 408 is surrounded with the fluid (water/ heat dissipating fluid) to facilitate heat dissipation during the surface treatment of the outer ring 408. Further, a gasket 410 is disposed between the top cover 406 and the middle cover 404 to prevent any leakage of the fluid from the attachment 112b. The assembly of the top cover 406 and the middle cover 404 are fixed to the bottom cover 402 by fastening means. Further, the attachment 112b is detachably connected to the rotary unit which rotates the attachment 112b at a pre-determined speed and simultaneously the inner surface of the outer ring 408 is exposed to the profiled laser beam for surface treatment. In an embodiment, the shape of the profiled laser beam is complementary to the profile of the inner surface of the outer ring 408.
Figure 5 illustrates still another attachment 112c that is configured to hold the roller element of the bearing. The attachment 112c comprises a holder assembly 502, a body cover 504, and a cap 506. The holder assembly 502 is enclosed by the cylindrical hollow body cover 504. Further, the holder assembly 502 is encapsulated between the cap 506 and the body cover 504, and is securely fastened by a bolt and nut assembly. In an embodiment, the holder assembly 502 is a magnetic assembly. Further, the holder assembly has an extended tapered tip. In an embodiment, the profile of the extended tapered tip is complementary to the side face diameter of the roller element providing easy alignment of the roller element with the holder assembly 502. In an operative configuration, when the surface of the roller element is to be surface treated, the attachment 112c is connected to the rotary unit 114 which rotates the attachment 112c at a pre-determined speed, against the laser being impinged on the surface of the rolling element. In an embodiment the arrangement of the attachment is such that, the central axis of the rolling element is aligned with the axis of the rotary unit 114 to provide uniform surface treatment of the rolling element. In an embodiment, the shape of the profiled laser beam being impinged on the rolling element is complimentary to the profile of the rolling element of the bearing.
As depicted in Figure 6, the present disclosure envisages a process 600 for treating the surface of the bearing components. The process 600 for treating the surface of the bearing components comprises the following steps:
At block 602, the process 600 includes the step of generating the laser beam by the laser source 102.
At block 604, the process 600 includes the step of focusing the generated laser beam, by the laser source 102, on the surface of at least one of the inner ring 308, the outer ring 408, and the rolling element, to perform surface treatment.
Figure 7A and Figure 7B illustrates graphs depicting a comparative analysis of the performance parameter of the system 100 of the present disclosure and the conventional system. An analysis was performed to evaluate the tensile strength of the laser surface treatment with the conventional surface treatment. In an embodiment, the bearing on which the laser surface treatment was carried out is a surface treated 3.0 mm thick flat SAE 52100 steel. Further, to evaluate the tensile strength of the laser surface treated bearing and the conventional surface treated bearing, a room temperature static tensile testing was carried out as per ASTM A370-15 standards with laser surface treatment being carried out under optimum processing conditions. Laser surface treated samples exhibited 1700 ± 30 MPa of tensile strength when compared to that of conventionally surface treated and tempered samples whose tensile strength is 1500 ± 50 MPa. The proposed laser surface treatment showed maximum improvement in tensile strength, i.e., by 25% due to the combination of residual stress.
Figure 8A and Figure 8B illustrates bar graphs depicting a comparative analysis of the tribological parameters of the laser surface treated sample with the conventional surface treated sample. The comparative sliding wear behavior was evaluated in terms of wear rate and the co-efficient of friction. The reported wear rate test was carried out as per ASTM G99-05 by employing ball-on-disc tribometer under 4.17GPa Hertzian contact pressures in both lubricated and dry conditions. The wear depth was substantially reduced in the laser surface treated sample compared to that of the conventional surface treated sample. A furthermore advantage of the invention is reduction in friction co-efficient i.e. 0.55 in dry condition and 0.075 in lubricated condition, due to Laser surface treatment as compared to the conventional surface treatment, whose values are 0.6 in dry and 0.1 in lubricated conditions. On the whole, the tribological improvement in the laser surface treatment could be attributed to hard refined martensitic transformation microstructure with modified carbide morphologies.
Thus, the results presented indicates vast improvement in various mechanical/tribological properties of laser surface treated bearing compared to conventionally surface treated bearing under optimum laser processing conditions and setups.
The envisaged system 100 and the process 600 results in martensitic with extremely fine carbides structures leading to higher hardness as compared to conventional surface hardening techniques like case-hardening or induction hardening on account of high cooling rates associated with localized process. The macro stresses that laser hardened surface generate is of high compressive nature. This happens due to formation of highly stressed martensite depending on the processing conditions and metallurgy of steel. The laser surface treatment of the bearing, of the present disclosure, facilitates in producing higher surface hardness, as high as 1000 HV.

TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a system for treating a surface of bearing components and a process thereof, that:
• increases the load carrying capacity of the bearings;
• improves the tribological properties of the bearings; and
• increases the fatigue strength of the bearings.
The disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully revealed 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 or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
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.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
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.