Description:TECHNICAL FIELD
[001] The present subject matter relates to a motor assembly, more particularly, a cover assembly for accommodating an encoder of the motor assembly.
BACKGROUND
[002] In general, a motor assembly is of two types, a radial motor, and an axial 5 motor. The above classification of motor assembly is determined on the basis of orientation and configuration of a central axis of the motor assembly, and the configuration of one or more stators and one or more rotors of the motor assembly.
[003] In general, the radial motor comprising a stator being disposed concentrically and coaxially along the central axis of the motor assembly. The stator 10 is concentrically disposed on a motor shaft and a rotor is disposed concentrically on the motor shaft. The rotor is disposed concentrically to the stator and the rotor is configured to surround the stator. The rotor is configured to have a plurality of magnets, and the plurality of magnets is disposed at a predetermined air gap from the stator. 15
[004] In the above configuration, the stator and the rotor is centrally disposed, and the stator remains in a stationary position during the motion of the motor assembly due to cancellation of the centripetal and centrifugal force from the stator and the rotor respectively.
[005] In general, the axial motor is constructed by aligning the stator and the 20 motor along the motor shaft of the motor assembly, with a predetermined air gap provided between the stator and the rotor. The rotor and the stator are not concentric to each other and is separated by the predetermined air gap. The axial motors are configured to have a plurality of combination of rotor and stator based on the power requirement and the required volume density of the motor assembly. Further an 25 encoder is provided in conjunction with a motor shaft of the motor assembly.
[006] In general, an encoder is a type of position sensor that provides feedback on the position, speed, and direction of a motor shaft or a rotor. The encoder plays a crucial role in accurately controlling and coordinating the motor's operation. Encoders work by detecting changes in magnetic fields, optical patterns, and other 30 physical properties to determine the position or displacement of the motor shaft.
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[007] In general, the encoder magnet and bush is disposed on end inside the motor shaft and the encoder magnet and bush is placed in proximity of a PCB (printed circuit board) which provides the input from the encoder sensor to a gear clutch assembly of the motor assembly. However, the placement of encoder magnet and bush inside the motor shaft leads to several challenges of serviceability, design 5 complexity, space consumption etc.
[008] In general, placing the encoder magnet and the encoder bush on the motor shaft, which has the rotor press-fitted onto it, can create difficulties in servicing the motor assembly. Further, if there is any damage to the encoder magnet or bush, the entire rotor assembly, along with the motor shaft, needs to be removed for repairs. 10 This process can be time-consuming and requires the expertise of highly skilled professionals to avoid any damage to the critical components on the motor shaft.
[009] Additionally, in order to access the encoder magnet and bush for maintenance or replacement, several components, such as the backend plate, phase cable connections, plastic clamps, and other fastening structures, need to be 15 disassembled. This complex disassembly process increases the chances of errors during reassembly, including proper placement and tightening torque. It adds to the overall complexity of the motor assembly and maintenance procedures.
[010] Furthermore, placing the encoder on the motor shaft requires a separate backend plate design, which increases the space consumed inside the motor 20 assembly. This additional space requirement can affect the overall size and compactness of the motor, making it less suitable for applications with limited space constraints.
[011] Additionally, placing the encoder on the motor shaft also introduce alignment challenges between the motor shaft and the stator and the rotor due 25 disposition of additional weight of the encoder on one end of the motor shaft. Ensuring precise alignment between the encoder and the motor components can be complex and time-consuming.
[012] Furthermore, the proximity of the encoder to other motor components on the motor shaft can result in signal interference. This interference can negatively 30
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impact the accuracy and reliability of the encoder's output signals and thereby inaccurate determination of direction of stator and rotor position occurs.
[013] Additionally, mounting the encoder directly on the motor shaft also amplify vibrations generated by the motor's operation. These vibrations can potentially affect the performance and lifespan of the encoder. 5
[014] Furthermore, placing the encoder on the motor shaft restricts the flexibility to modify or upgrade the encoder independently of the motor. Upgrading or replacing the encoder may require disassembling the entire motor assembly, leading to additional time and effort.
[015] Furthermore, the choice of encoders is limited when placed on the motor 10 shaft due to space constraints and compatibility issues related to shape and dimension of the encoder. This limitation can restrict the use of specific encoder types to be used which can reduce the efficiency of the motor.
[016] Moreover, during high speed operation of the motor, the encoder magnet comes into contact with mechanical parts of the motor assembly, such as bush 15 terminals of line wires of the motor assembly. This causes disintegration and damage of the encoder magnet and thereby reduces the efficiency of the motor assembly.
[017] Additionally, a driven shaft of the motor assembly is subjected to rotational movement and vibrations during motor running condition, which can result in unwanted variations and disturbances in the encoder readings. This can lead to 20 inaccuracies in determining the position, speed, and direction of the motor. Additionally, the driven shaft may experience different levels of mechanical stress and load compared to the motor shaft, further affecting the reliability and consistency of the encoder measurements.
[018] Hence, careful design considerations and implementation of suitable 25 measures, such as proper shielding and robust mounting, are necessary to mitigate these issues and ensure precise and consistent encoder performance.
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SUMMARY
[019] The present subject matter provides a motor assembly housing encasing a drive gear and a driven gear of a gear system and an encoder sensor being disposed inside a driven shaft of the driven gear for ease of assembly and ease of serviceability of the motor assembly. 5
[020] As per an aspect of the present invention, a motor assembly comprising at least one rotor and at least one stator, a housing and a gear system. The at least one rotor and the at least one stator is disposed inside the housing. The gear system comprising a drive gear and a driven gear. The drive gear is in contact with the at least one rotor. The driven gear is in contact with one or more electronic components 10 encased in the housing for ease of serviceability of the motor assembly.
[021] As per an embodiment, the gear system being one of a belt type gear system and a reduction gear system. The gear system is also one of an integrated gear system of the motor assembly and an external gear box being connected with the at least one rotor of the motor assembly. 15
[022] As per another embodiment, the driven gear is provided with a driven gear shaft and a driven gear bush. The drive gear is connected with a motor shaft (110) and also provided with a drive gear bush.
[023] As per another embodiment, the driven gear shaft includes a magnet, and the magnet is press fitted inside one end of the drive gear shaft. 20
[024] As per another embodiment, the one or more electronic components is an encoder sensor, and the one or more electronic components is attached on a PCB and the driven gear is in contact with the one or more electronic components.
[025] As per another embodiment, the one or more electronic components is disposed inside an enclosure and the enclosure is configured to enclose the entire 25 assembly of the one or more electronic components, the PCB, the driven gear shaft and the driven gear. The enclosure is then covered with a cover.
[026] As per another embodiment, the PCB is mounted on a plurality of mounting points through a plurality of fasteners. The plurality of mounting points is integrated with the enclosure and the plurality of mounting points is disposed one or 30 more peripheral corners of the enclosure.
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[027] As per another embodiment, the enclosure is integrated with the housing for accommodating the driven gear and one of the housing is configured for accommodating the drive gear and the motor shaft.
[028] As per another embodiment, the driven gear rotates at a first angular momentum, and the drive gear rotates at a second angular momentum, and wherein 5 the first angular momentum being twice of the second angular momentum . The first and the second angular momentum being in a range of 0 to 360 degrees with a step value of 0.001 degree.
[029] As per another embodiment, the cover is rotated in a clockwise direction and tightened to cover the PCB. The cover is rotated in an anti-clockwise direction 10 to replace the PCB and the one or more electronic components for ease of serviceability.
[030] As per another embodiment, the enclosure is provided on an extension of the one of the housing, and the extension being integral to the one of the housing. The gear system is covered and secured by a gear system cover. 15
[031] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPT ION OF THE DRAWINGS 20
[032] The present invention is described with reference to figures. This invention is implementable in two-wheeled, three wheeled and four wheeled vehicles and any other electrical appliances using an axial motor. The same numbers are used throughout the drawings to reference features and components. Further, the inventive features of the invention are outlined in the appended claims. 25
[033] Figure 1 illustrates an exploded view of a motor assembly, in accordance with an embodiment of the present subject matter.
[034] Figure 2 illustrates a perspective view of an integrated gear system disposed in a housing of the motor assembly, in accordance with an embodiment of the present subject matter. 30
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[035] Figures 3a, 3b illustrates a cross section view of a belt type and a reduction gear system respectively in the motor assembly along a vertical axis, in accordance with an embodiment of the present subject matter.
[036] Figure 4 illustrates an exploded view of the integrated gear system disposed in the housing of the motor assembly, in accordance with an embodiment 5 of the present subject matter.
[037] Figure 5 illustrates a front view of the integrated gear system of the motor assembly, in accordance with an embodiment of the present subject matter.
[038] Figure 6a and 6b illustrates a perspective view of the reduction gear system and the belt type gear system disposed in the housing of the motor assembly, 10 in accordance with an embodiment of the present subject matter.
DETAILED DESCRIPTION OF THE DRAWINGS
[039] Exemplary embodiments are described with reference to the 15 accompanying drawings. Wherever convenient, the same reference numbers are used throughout the drawings to refer to the same or like parts. While examples and features of disclosed principles are described herein, modifications, adaptations, and other implementations are possible without departing from the scope of the disclosed embodiments. It is intended that the following detailed description be considered as 20 exemplary only, with the true scope being indicated by the following claims.
[040] The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate the principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the 25 principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[041] The foregoing disclosure is not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated 30 that various alternate embodiments and/or modifications to the present disclosure,
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whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the claims. 5
[042] Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, “primary”, “secondary”, “main” or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, 10 particularly as to the order, or preference, of any element, embodiment, variation and/or modification relative to, or over, another element, embodiment, variation and/or modification.
[043] Hence it is an object of the present invention to provide a motor assembly with a configuration of an encoder being disposed in a driven shaft of the motor 15 assembly for ease of serviceability of the motor assembly and also to overcome other related problems known in the art as explained in the background problem.
[044] It is also an object of the present invention to reduce overall part count and eliminate use of multiple mounting brackets for mounting the PCB and the encoder on the driver shaft. 20
[045] It is also an object of the present invention to reduce the breakage and damage of the encoder when disposed in the driver shaft and therefore increase life span of the encoder.
[046] It is also an object of the present invention to provide ease of serviceability and maintenance of the gear system and the encoder of the motor assembly. 25
[047] It is also an object of the present invention to reduce noise and vibrations emanating from the motor assembly.
[048] It is also an object of the present invention to accommodate the encoder in limited space of the motor assembly and also to enable usage of different configurations of the encoder to enhance efficiency of the motor assembly. 30
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[049] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
[050] Figure 1 illustrates an exploded view of a motor assembly (100), in accordance with an embodiment of the present subject matter. A motor assembly (100) is an axial motor assembly is one embodiment. The motor assembly (100) 5 comprises a housing (102a, 102b). The housing (102a, 102b) being split into one or more parts and includes a first part (102a) and a second part (102b) in one embodiment. The first part (102a) and the second part (102b) conform with each other in shape, size, dimensions, and profile. The housing (102a, 102b) includes a central projection (102c) for receiving a motor shaft (110) of the motor assembly 10 (100). The motor shaft (100) is disposed between the housing (102a, 102b) and is sandwiched fixedly between the first part (102a) and the second part (102b) through a first bearing (104a) and a second bearing (104b).
[051] The motor assembly (100) further comprising at least one stator (108) and at least one rotor (106a, 106b). The at least one stator (108) is disposed and 15 sandwiched between the at least one rotor (106a, 106b) in one embodiment. In another embodiment, the at least one rotor (106a, 106b) is sandwiched and disposed between the at least one stator (108). The at least one stator (108) and the at least one rotor (106a, 106b) being disposed on the motor shaft (110) and the at least one stator (108) and the at least one rotor (106a, 106b) is centrally and coaxially disposed 20 on the motor shaft (110). The at least one stator (108) and the at least one rotor (106a, 106b) is attached on the motor shaft (110) and the housing (102a, 102b) through one or more fasteners (112). This configuration provides a compact packaging of the at least one stator (108) and the at least one rotor (106a, 106b) of the motor assembly (100). 25
[052] The housing (102a, 102b) is also provided to accommodate a gear system (114) of the motor assembly (100). The gear system (114) includes a drive gear (122) and a driven gear (124). In one embodiment, the gear system (114) is an integrated gear system being integral with the housing (102a, 102b). In another embodiment, the gear system (114) is an external gear box being attached to the motor assembly 30 externally and the external gear box being in contact with the at least one rotor (106a,
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106b). In one embodiment, the gear system (114) being a belt type gear system and in another embodiment, the gear system (114) is a reduction gear system. The gear system (114) has a casing extension (114b) being integrally attached to the housing (102a, 102b). The drive gear (122) has a drive gear bush (122a, 122b) and the drive gear is attached to the motor shaft (110). The driven gear (124) is provided with a 5 driven gear shaft (126) and a driven gear bush (124a, 124b). The driven gear (124) along with the driven gear shaft (126) is disposed inside the casing extension (114b) and is secured to a PCB (118) using fasteners (120). The driven gear shaft (126) also includes one or more electronic components being press fitted inside it and being in contact with the PCB (118). 10
[053] Figure 2 illustrates a perspective view of an integrated gear system disposed in a housing (102a, 102b) of the motor assembly (100), in accordance with an embodiment of the present subject matter. The gear system (114) is an integrated gear system, and the gear system (114) is integrally attached to the second part (102b) of the housing (102a, 102b). The casing extension (114b) of the gear system 15 (114) extends longitudinally upwards from the second part (102b) of the housing (102a, 102b). The PCB (118) is secured in the casing extension (114a) through one or more fasteners (120) and the PCB (118) along with the driven gear shaft (126) is secured inside a cover (116). The cover (116) is rotated in a clockwise direction to tighten and secure the PCB (118) and the cover (116) is rotated in an anti-clockwise 20 direction to remove the cover (116) during serviceability of the motor assembly (100).
[054] Figures 3a, 3b illustrates a cross section view of a belt type and a reduction gear system respectively in the motor assembly along a vertical axis, in accordance with an embodiment of the present subject matter. The drive gear (122) is mounted 25 to the motor shaft (110) and the driven gear shaft (126) includes an encoder magnet (130) disposed on one end of the driven gear shaft (126). In one embodiment, the magnet (130) is disposed in proximity to the PCB (118) and the PCB (118) includes the one or more electronic components. In one embodiment, the one or more electronic components is an encoder sensor. In one embodiment, the drive gear (122) 30 and the driven gear (124) are in contact with each other in a reduction gear system,
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as shown in figure 3b. In another embodiment, the drive gear (122) and the driven gear (124) is separated by a belt for transmitting the power of the motor assembly (100) to the driven gear (124) in a belt type transmission system, as shown in figure 3a. In one embodiment, the diameter of the driven gear (124) is twice than the diameter of the drive gear (122). In another embodiment, the driven gear (124) has 5 twice the number of teeth than the drive gear (122). In another embodiment, the driven gear (124) rotates with a first angular momentum and the drive gear (122) rotates with a second angular momentum, and the first angular momentum is twice the second angular momentum. The first and the second angular momentum lies within a range of 0 to 360 degrees with an incremental step value of 0.001 degree. 10
[055] Figure 4 illustrates an exploded view of the integrated gear system disposed in the housing of the motor assembly (100), in accordance with an embodiment of the present subject matter. The casing extension (114b) of the gear system (114) includes an enclosure (103b) for accommodating the PCB (118) from a first end and also for accommodating the driven gear (124) and the driven gear 15 shaft (126) from an opposite end. The PCB (118), the driven gear (124) and the driven gear shaft (126) are attached to each other and secured inside the enclosure (103b) using the one or more fasteners (120). The enclosure (103b) has plurality of threads on an outer surface for receiving the cover (116). The cover (116) also has plurality of inner threads to securely configure with the threads of the enclosure 20 (103b).
[056] Figure 5 illustrates a front view of the integrated gear system of the motor assembly (100), in accordance with an embodiment of the present subject matter. Figure 6a and 6b illustrates a perspective view of the reduction gear system and the belt type gear system disposed in the housing of the motor assembly (100), in 25 accordance with an embodiment of the present subject matter. For brevity figures 5, 6a and 6b will be discussed together. The enclosure (103b) of the casing extension (114a) includes plurality of mounting holes (200). The plurality of mounting holes (200) are disposed on the outer peripheral boundary of the enclosure (103b). The plurality of mounting holes (200) are disposed in at least four corners of the 30 enclosure (103b) in one embodiment. The enclosure (103b) is provided with a central
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opening (202) for the driven gear shaft (126) to pass through. The plurality of mounting holes (200) are configured to mount the PCB (118) with the one or more electronic components disposed on the PCB (118), along with the driven gear shaft (126) through the one or more fasteners (120). In one embodiment, the belt of the gear system (114) is also disposed inside the casing extension (114b) between the 5 drive gear (122) and the driven gear (124).
[057] Various embodiments of the invention provides a motor assembly housing encasing a drive gear and a driven gear of a gear system and an encoder sensor being disposed inside a driven shaft of the driven gear for ease of assembly and ease of serviceability of the motor assembly. 10
[058] The present invention is a motor assembly comprising at least one rotor and at least one stator, a housing and a gear system. The at least one rotor and the at least one stator is disposed inside the housing. The gear system comprising a drive gear and a driven gear. The drive gear is in contact with the at least one rotor. The driven gear is in contact with one or more electronic components encased in the 15 housing for ease of serviceability of the motor assembly.
[059] The present claimed invention solves the technical problem of damage of an encoder magnet due to continuous usage and also difficulty in maintenance and serviceability of the motor assembly due to removal of all the allied parts of the motor assembly in order to replace the encoder and the encoder magnet. 20
[060] Specifically, the claimed motor assembly provides ease of serviceability and replaceability of the encoder and the encoder magnet by removal of the cover without disassembling allied parts of the motor assembly.
[061] Additionally, the encoder magnet being disposed in the driven gear shaft instead of the motor shaft increases the life span of the encoder magnet as the 25 movement of the direct rotational movement of the encoder magnet is restricted along with the motion of the rotor. Thus, the damage and breakage of the encoder magnet is also reduced.
[062] Furthermore, the noises and vibrations from the rotor is not transferred directly to the encoder and the encoder magnet in the present invention. This 30
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provides accurate reading of the direction and speed of the rotor without any interference from vibrations of the rotor movement.
[063] The present invention also provides advantages of customization of the encoder and the encoder magnet due to availability of space in the driven gear shaft, since the driven gear shaft is diametrically larger than the motor shaft. This in turn 5 increases the overall efficiency of the motor assembly.
[064] In light of the above-mentioned advantages and the technical advancements provided by the disclosed motor assembly comprising the encoder magnet being disposed on the driven gear shaft and the encoder being covered by a gear system cover, the claimed invention as discussed above is not routine, 10 conventional, or well understood in the art, as the claimed invention enable the following solutions to the existing problems in conventional technologies. Further, the claimed invention clearly bring an improvement in the configuration and construction of the motor assembly and also aids in serviceability and maintenance of the motor assembly without disassembly of crucial parts of the motor assembly 15 as the claimed invention provide a technical solution to a technical problem.
[065] While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention. 20
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Reference Numerals:
100 motor assembly
102a, 102b housing 5
104a, 104b first and second bearing
106a, 106b at least one rotor
108 at least one stator
110 motor shaft
112 one or more fasteners 10
114a casing extension
114 gear system
118 PCB
113b enclosure
114b gear casing 15
120 one or more fasteners
116 cover
122 drive gear
122a, 122b drive gear bush
124 driven gear 20
124a, 124b driven gear bush
126 driven gear shaft
130 magnet
200 plurality of mounting holes
202 central hole , Claims:I/We claim:
1. A motor assembly (100), said motor assembly (100) comprising:
at least one rotor (106a, 106b);
at least one stator (108);
a housing (102a, 102b); and 5
a gear system (114);
wherein said at least one rotor (106a, 106b) and said at least one stator (108) being disposed inside said housing (102a, 102b);
wherein said gear system (114) comprising a driver gear (122) and a driven gear (124), and said drive gear (122) being in contact with 10 said at least one rotor (106a, 106b); and
wherein said driven gear (124) being configured to be in contact with one or more electronic components encased in said housing (102a, 102b) of said motor assembly (100) for ease of serviceability of said motor assembly (100). 15
2. The motor assembly (100) as claimed in claim 1, wherein said gear system (114) being one of a belt type gear system and a reduction gear system.
3. The motor assembly (100) as claimed in claim 1, wherein said gear system (114) being one of an integrated gear system of said motor assembly (100) and an external gear box being in contact with said at least one rotor (106a, 20 106b).
4. The motor assembly (100) as claimed in claim 1, wherein said driven gear (124) being provided with a driven gear shaft (126) and a driven gear bush (124a).
5. The motor assembly (100) as claimed in claim 1, wherein said drive gear 25 (122) being connected with a motor shaft (110) and a drive gear bush (122a).
6. The motor assembly (100) as claimed in claim 4, wherein said driven gear shaft (126) including a magnet (130), said magnet (130) being press fitted inside one end of said driven gear shaft (126).
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7. The motor assembly (100) as claimed in claim 1, wherein said one or more electronic components being an encoder, said one or more electronic components being disposed on a PCB (118), and wherein said driven gear (124) being in contact with said one or more electronic components and said PCB (118). 5
8. The motor assembly (100) as claimed in claim 7, wherein said one or more electronic components being disposed on said PCB (118), and said PCB (118) being disposed inside an enclosure (103b), said enclosure (103b) being configured to enclose said one or more electronic components, said PCB (118), said driven gear shaft (126) and said driven gear (124) together, 10 wherein said enclosure (103b) being covered with a cover (116).
9. The motor assembly (100) as claimed in claim 8, wherein said PCB (118) being mounted on a plurality of mounting points (200) through a plurality of fasteners (120) and said plurality of mounting points (200) being integrated with said enclosure (103b), and wherein said plurality of 15 mounting points (200) being disposed on one or more peripheral corners of said enclosure (103b).
10. The motor assembly (100) as claimed in claim 8, wherein said enclosure (103b) being integrated with said housing (102a, 102b) for accommodating said driven gear (124), and wherein one of said housing (102a, 102b) being 20 configured for accommodating said drive gear (122) and said motor shaft (110).
11. The motor assembly (100) as claimed in claim 1, wherein said driven gear (124) being configured to rotate at a first angular momentum and said drive gear (122) being configured to rotate at a second angular momentum, and 25 wherein said first angular momentum being twice of said second angular momentum, wherein said first and second angular momentum being in a range of 0 to 360 degrees and a step value of 0.001 degrees.
12. The motor assembly (100) as claimed in claim 8, wherein said cover (116) being rotated in clockwise direction and secured to cover said PCB (118), 30 and wherein said cover (116) being configured to be rotated in an
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anticlockwise direction to replace said PCB (118) and said one or more electronic components.
13.The motor assembly (100) as claimed in claim 8, wherein said enclosure(113b) being provided on a casing extension (114b) of said housing (102a,102b), and wherein said casing extension (114b) being integral to said one5 of said housing (102a, 102b), and wherein said gear system (114) beingcovered and secured by a gear system cover (114a).
Dated 19 day of July 2023