FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See Section 10; rule 13] "COMMUTATION ASSEMBLY FOR AN ELECTRIC MOTOR"
PORTESCAP INDIA PVT. LTD.,
an Indian Entity,
of Unit No. 2, SDF 1 Seepz SEZ,
Andheri East Mumbai – 400096, India
The following specification particularly describes the invention and the manner in
which it is to be performed

FIELD OF INVENTION
[001] The present invention generally relates to a commutation assembly for electric motors, and more specifically pertains to a commutation assembly for a DC motor capable of prolonging life of a motor.
BACKGROUND OF THE INVENTION
[002] A DC motor is a rotary electrical machine that converts direct current electrical energy into mechanical energy. The most common types of DC motors rely on the forces produced by magnetic fields, and typically incorporate some internal mechanism, either electromechanical or electronic, to periodically change the direction of current flow in part of the motor.
[003] A typical DC motor has a stationary set of magnets in a stator and an armature with one or more windings of insulated wire wrapped around a soft iron core that concentrates the magnetic field. The windings usually have multiple turns around the core, and in large motors there can be several parallel current paths. The ends of the wire windings are connected to a commutator. The commutator allows each armature coil to be energized in turn and connects the rotating coils with the external power supply through brushes.
[004] Depending on the type of armature winding used in a four-pole DC motor, number of brush arms in a lap connected motor are typically equal to the number of poles, and for a wave connected motor the number of brush arms are equal to 2. Each brush arm may have several brush holders depending upon the amount of current to be passed through.
[005] In a convention two-pole brush DC motor, there are two pair of brushes placed in the same plane at 180 degrees apart. In a four-pole brush DC motor, two additional pairs of brushes are placed in the same plane, in a similar manner as in case of a typical two-pole brush DC motor. This kind of arrangement doubles the commutator wear due to the additional pair of brush added for the four-pole motor design. This is due to the fact that the same area of commutator is subjected to mechanical wear and tear, and

electrical erosion of the commutator as well as the brushes is also predominant in such cases. The motor life depends on life of the commutator and the brushes and with such an arrangement, the motor life is significantly reduced.
[006] In view of the foregoing, there is a need for techniques that are capable of substantially reducing mechanical wear and tear as well as electrical erosion of the commutator and the brushes which will lead to a prolonged life of the motor.
OBJECTS OF THE INVENTION
[007] It is an object of the present invention to provide a commutation assembly which improves life of an electric motor.
[008] It is another object of the present invention to provide a highly reliable commutation assembly capable of efficiently prolonging life of commutator and brushes of the electric motor.
[009] It is another object of the present invention to provide a commutation assembly which substantially reduces mechanical wear and tear between the commutator and the brushes of the electric motor.
[010] It is another object of the present invention to provide a commutation assembly which envisages to reduce electrical erosion of the commutator and the brushes of the electric motor.
[011] It is yet another object of the present invention to provide a commutation assembly which envisages to improve reliability, repairability, and maintainability of the electric motor, while at the same time reducing down time of the electric motor.
SUMMARY OF THE INVENTION
[012] An aspect of the present invention relates to a commutation assembly for reducing mechanical wear and tear between brushes and commutator of an electric motor as well as reducing electrical erosion of the commutator and the brushes. The commutation assembly includes a commutator connected to an armature of the electric motor, a first set of brushes arranged in a first plane over length of the commutator,

each brush of said first set of brushes being pivoted at one end with the other end being in contact with the commutator in the first plane, and a second set of brushes arranged in a second plane over the length of the commutator, each brush of said second set of brushes being pivoted at one end with the other end being in contact with the commutator in the second plane. The first set of brushes are spaced apart from the second set of brushes over the length of the commutator to disperse wear and tear between the first and second sets of brushes and the commutator in the first plane and the second plane.
[013] According to an embodiment of the present invention, the commutation assembly further includes a first set of constant force springs, each spring of the first set of constant force springs adapted to maintain contact between each brush of said first set of brushes and the commutator in the first plane. According to another embodiment of the present invention, the commutation assembly includes a second set of constant force springs, each spring of the second set of constant force springs adapted to maintain contact between each brush of said second set of brushes and the commutator in the second plane.
[014] According to an embodiment of the present invention, length of the commutator is adapted to accommodate positioning and alignment of the first set of brushes and the second set of brushes in the first plane and the second plane, respectively, over the length of the commutator respectively.
[015] According to an embodiment of the present invention, positioning as well as height of the first set of constant force springs and the second set of constant force springs is adapted to maintain continuous contact between the first and second sets of brushes and the commutator in the first plane and the second plane, respectively.
[016] According to an embodiment of the present invention, the commutation assembly also includes a set of locking mechanisms adapted to adjust positioning and alignment of the first and second sets of constant force springs to ensure continuous contact between the first and second sets of brushes and the commutator in the first plane and the second plane respectively.

[017] According to an embodiment of the present invention, the commutation assembly includes a set of platforms for accommodating height adjustment of any or a combination of the first and second sets of constant force springs. According to an embodiment of the present invention, the set of platforms are adapted to accommodating height and position adjustment of any or a combination of the first and second sets of brushes arranged in the first plane and the second plane, respectively, over the length of the commutator.
[018] According to an embodiment of the present invention, the first set of brushes in the first plane is spaced apart from the second set of brushes over the length of the commutator in the second plane to disperse wear and tear between the first and second sets of brushes and the commutator in a first wear region and a second wear region, respectively.
[019] According to an embodiment of the present invention, the commutation assembly includes a commutation housing adapted to accommodate the commutator, the first and second sets of brushes and the first and second sets of constant force springs.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[020] The accompanying drawings are included to provide a further understanding of the present disclosure, are incorporated in, and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[021] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[022] Fig. 1A illustrates an exemplary representation of the commutation assembly for an electric motor, in accordance with an embodiment of the present invention;
[023] Fig. 1B illustrates an exemplary plan view representation of the commutation assembly, in accordance with an embodiment of the present invention; and
[024] Fig. 2 illustrates an exemplary perspective view representation of the commutation assembly showing a first plane and a second plane of commutation wear area, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[025] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[026] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This disclosure may however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future.
[027] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention, and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed

description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. The embodiment provided herein is for the purpose of filing the present provisional specification; however, further embodiments within this disclosure are possible and shall/may be covered in the complete specification.
[028] The present invention relates to a commutation assembly for an electric motor, for instance, a four-pole DC motor, which is capable of prolonging life of the motor by reducing frictional wear and tear between a commutator and brushes of the motor, and reducing electrical erosion of the commutator and the brushes. This in turn enhances reliability, repairability and maintainability of the motor, while at the same time reduces down time of the electric motor.
[029] According to an embodiment, the present invention envisages to reduce the impact of electrical erosion and frictional wear and tear of the brushes and the commutator of the motor in a single contact region by dissipating/dispersing the wear and tear in different regions over length of the commutator, thereby providing a relief for conventional DC motors, components of which are subjected to continuous wear and tear in a single plane which ultimately leads to motor failure and calls for repair/replacement of such components.
[030] Figs. 1A and 1B illustrate exemplary representations of the commutation assembly for the electric motor. In an aspect of the present invention, the commutation assembly includes a commutator (100) connected with an armature of the electric motor through which electrical connection is made and which ensures that current flows as direct current. A first set of electrical contacts (110) (also referred to as “brushes” hereinafter) is arranged in a first plane (200) (as shown in Fig. 2) over length of the commutator (100) to make sliding contact with the commutator (100) in the first plane (200) as it rotates. A second set of brushes (130) is arranged in a second plane (210) (as shown in Fig. 2) over length of the commutator (100) to make sliding contact with the commutator (100) in the second plane (210) as it rotates. To adjust the first set of brushes (110) and the second set of brushes (130) in different planes, boss

members having different heights may be used. For instance, the first set of brushes (110) may be positioned over a first set of boss members (185) having a first predefined height, to position the first set of brushes (110) in the first plane (200). Similarly, the second set of brushes (130) may be positioned over a second set of boss members (190) having a second predefined height, to position the second set of brushes (130) in the second plane (210).
[031] According to an embodiment of the present invention, each brush of the first set of brushes (110) is pivoted at one end with the other end being in contact with the commutator (100) in the first plane (200). According to another embodiment of the present invention, each brush of the second set of brushes (130) is pivoted at one end with the other end being in contact with the commutator (100) in the second plane (210).
[032] According to an embodiment of the present invention, the commutator (100) may have a length which accommodates position and alignment of the set of brushes farthest from its base to ensure continuous sliding contact between its surface and all the brushes for optimal performance of the motor.
[033] According to an embodiment of the present invention, the first set of brushes (110) arranged in the first plane (200) are spaced apart from the second set of brushes (130) arranged in the second plane (210) over the length of the commutator (100) which enables distribution/dispersion of electrical erosion and mechanical wear and tear between the first and second sets of brushes (110; 130) and the commutator (100) in the first plane (200) and the second plane (210).
[034] According to an embodiment of the present invention, continuous sliding contact between the first and second sets of brushes (110; 130) and the commutator (100) is maintained by constant force spring position and alignment of which may be adjustable to compensate wear and tear of the brushes (110; 130). The commutation assembly includes a first set of constant force springs (120) for maintaining sliding contact between the first set of brushes (110) and the commutator (100) in the first plane (200) as the commutator (100) rotates. Also, the commutation assembly includes a second set of constant force springs (140) for maintaining sliding contact between

the second set of brushes (130) and the commutator (100) in the second plane (210) as the commutator (100) rotates.
[035] According to an embodiment of the present invention, each of the first and second set of constant force springs (120; 140) may ensure that sliding contact of each brush of the first and second sets of brushes (110; 130) and the commutator (100) is maintained. According to an embodiment of the present invention, height of the constant force springs (120; 140) may be adjusted to maintain continuous sliding contact between the brushes (110; 130) and the commutator (100) in the first plane (200) and the second plane (210) respectively.
[036] According to an embodiment of the present invention, positioning and alignment of the first set of constant force springs (120) and the second set of constant force springs (140) may be adjusted by a set of locking mechanisms (160) and (170) respectively to ensure that constant spring forces are constantly applied by the constant force springs (120; 140) to the first and second sets of brushes (110; 130). In this manner, continuous sliding contact will be maintained between the first and second sets of brushes (110; 130) and the commutator (100) in the first plane (200) and the second plane (210), respectively.
[037] According to an embodiment of the present invention, a set of platforms (150) are configured to accommodate height and position adjustment of the brushes (110; 130) and the constant force springs (120; 140) along the length of the commutator (100).
[038] Fig. 2 illustrates an exemplary perspective view representation of the commutation assembly showing the reduction in mechanical wear and tear of the commutator and brushes of the electric motor.
[039] According to an embodiment of the present invention, the first plane (200) is spaced apart from the second plane (210) along the length of the commutator (100) by a pre-determined distance to allow generation of frictional wear and tear between the brushes (110; 130) and the commutator (100) in a first wear region (220) of the first plane (200) and a second wear region (230) of the second plane (210) respectively,

thereby distributing the frictional wear and tear between the brushes (110; 130) and the commutator (100) in different wear regions.
[040] Therefore, the impact of wear and tear in the first wear region (220) of the first plane (200) is substantially reduced since the sliding contact between the second set of brushes (130) and the commutator (100) is shifted to the pre-determined distance along the length of the commutator (100) in the second wear region (230) of the second plane (210) which results in reduction in electrical erosion and frictional wear and tear of both the first and second sets of brushes (110; 130) and the commutator (100). Such an arrangement prolongs life of the brushes (110; 130) and the commutator (100) and reduces the requirement of regular repair/replacement of such components, a condition with which the conventional four-pole DC motors are plagued.
[041] It is clearly illustrated that the proposed arrangement is effective in terms of both cost and accommodation. All the components including the first and second sets of brushes (110; 130), the first and second sets of constant force springs (120; 140), the set of locking mechanisms (160) and (170), and the set of platforms (150) may be accommodated over the commutation housing (180) while still allowing other necessary components to be accommodated over the commutation housing (180). Further, since the number of components required to attain the objectives of the present invention is small, repairability of the DC motor is improved.
[042] Thus, the present invention provides a technique to reduce mechanical wear and tear between the brushes and the commutator to improve life of the brushes and the commutator which further results in improvement of life of the DC motor while increasing reliability and repairability of the DC motor. In the present invention, the commutator is connected with the armature of the electric motor. The first set of brushes and the second set of brushes are arranged in the first plane and the second plane respectively, which are spaced apart from each other over length of the commutator to enable dispersion/distribution of frictional wear and tear between the first and second sets of brushes and the commutator in the first wear region (shown in Fig. 3) of the first plane and the second wear region (shown in Fig. 3) of the second

plane, to thereby reduce the impact of frictional wear and tear in a single plane as is the case in a conventional four-pole DC motor.
[043] Various modifications to these embodiments are apparent to those skilled in the art from the description and drawings herein. The principles associated with the various embodiment defined herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be provided broadest scope consistent with the principles and novel and inventive features describe/disclosed or suggested herein. Any modifications, equivalent substitutions, improvements etc. within the principle of the present invention shall all be included in the scope of protection of the present invention.

DESC:AS ENCLOSED ,CLAIMS:We Claim:
1. A commutation assembly for an electric motor, the commutation assembly comprising:
a commutator (100) comprising a plurality of commutator segments arranged around an axis of rotation , wherein the plurality of commutator segments are 5 connected to an armature of the electric motor;
a first set of brushes (110) arranged in a first plane (200) , around the commutator (100), and positioned over a first set of boss members (185) having a first predefined height, wherein the first set of brushes (110) makes a sliding contact with the commutator (100) in the first plane (200); and 10
a second set of brushes (130) arranged in a second plane (210), around the commutator (100), and positioned over a second set of boss members (190) having a second predefined height, wherein the second set of brushes (130) makes a sliding contact with the commutator (100) in the second plane (210).
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2. The commutation assembly as claimed in claim 1, wherein the electric motor is a four pole Direct Current (DC) motor.
3. The commutation assembly as claimed in claim 1, comprising a first set of constant force springs (120) fixed on commutation housing (180) and behind the first 20 set of brushes (110), wherein the first set of constant force springs (120) apply spring force to the first set of brushes (110) for maintaining continuous contact with the commutator (100).
4. The commutation assembly as claimed in claim 3, comprising a first set of 25 locking mechanism (160) fixed on commutation housing (180) and present adjacent to the first set of constant force springs (120), wherein the first set of locking mechanism (160) ensures continuous application of spring force by the first set of constant force springs (120) to the first set of brushes (110).
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5. The commutation assembly as claimed in claim 1, comprising a second set of constant force springs (140) fixed over a set of platforms (150) and behind the second set of brushes (130), wherein the second set of constant force springs (120) apply spring force to the second set of brushes (130) for maintaining continuous contact with the commutator (100). 5
6. The commutation assembly as claimed in claim 5, comprising a second set of locking mechanism (170) fixed over the set of platforms (150) and present adjacent to the second set of constant force springs (140), wherein the second set of locking mechanism (170) ensures continuous application of spring force by the second set of 10 constant force springs (140) to the second set of brushes (130).
7. The commutation assembly as claimed in claim 5, wherein the set of platforms (150) enables distribution of electrical erosion and mechanical wear between the first sets of brushes (110) and the commutator (100) in the first plane (200), and between 15 the second set of brushes (130) and the commutator (100) in the second plane (210).
8. The commutation assembly as claimed in claim 7, wherein a height of the set of platforms (150) results in distribution of wearing of the commutator (100) into a first wear region (220) and a second wear region (230), present in different planes. 20
Dated this 06/09/2019
[JAYANTA PAL]
IN/PA No. 172
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANT[S]