FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
“A STATOR ASSEMBLY FOR AN INDUCTION MOTOR”
We, Bajaj Electricals Limited, an Indian National, of, 45/47, Veer Nariman Road, Fort, Mumbai - 400001, Maharashtra, India.
The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF INVENTION
The present disclosure generally relates to an electric motor for ceiling fans. More particularly, the present disclosure relates to a stator lamination deployed for a single-phase induction motor of a ceiling fan.
BACKGROUND OF THE INVENTION
This section is intended to provide information relating to the field of the invention and thus, any approach or functionality described below should not be assumed to be qualified as prior art merely by its inclusion in this section.
Ceiling fans are commonly known to employ an electric motor for rotating a plurality of fan blades, and thus generating an airflow. It is commonly known that in conventional ceiling fans, a single-phase induction motor is employed as the electric motor because of their low cost and simple construction. A single-phase induction motor is commonly known to include a stator assembly and a rotor assembly, wherein the stator assembly is a stationary component, while the rotor assembly is a squirrel-cage type moving component of the single-phase induction motor.
It is typically known that the stator assembly comprises of a stack of stator laminations arranged together, structured and arranged to allow routing of main windings as well as auxiliary windings therethrough. Conventionally, a stator lamination comprises a plurality of main winding slots and a plurality of auxiliary winding slots, for allowing the passing of the main windings and the auxiliary windings therethrough. Notably, the plurality of main winding slots and the plurality of auxiliary winding slots are defined at different radial lengths in the stator lamination.
It may further be noted that an efficiency of the single-phase induction motor highly depends on copper losses and core losses, which are required to be

optimized for increased efficiency thereof. For reducing the copper losses, it is required to reduce current in winding and resistance of the winding thus an optimized amount of copper of the main windings and the auxiliary windings is required, which may result in increase in area of the plurality of main winding slots and the plurality of auxiliary winding slots. However, a substantially increase in the area of the plurality of main winding slots and the plurality of auxiliary winding slots, may cause increase in the core losses. An increase in any of the copper losses and/or core losses causes reduction in overall efficiency of the single-phase induction motor.
Accordingly in light of the aforementioned drawbacks and several other limitations inherent in the existing art, there is a well felt need to provide improved stator lamination with optimized size of the plurality of main winding slots and the plurality of auxiliary winding slots, to optimize and balance copper losses and core losses, for increasing an overall efficiency of the single-phase induction motor.
SUMMARY OF THE PRESENT INVENTION
This section is intended to introduce certain objects of the disclosed method and system in a simplified form and is not intended to identify the key advantages or features of the present disclosure.
The present disclosure relates to a stator assembly for an induction motor employed in a ceiling fan, the stator assembly comprising: a stack of stator laminations, each stator laminations defining a plurality of main winding slots and a plurality of auxiliary winding slots at pre-defined radial lengths extending radially inwards from an outer periphery, wherein each of the plurality of main winding slots defines: a main slot (Som)opening, a main opening angle (ANGm), a main tooth tip thickness (TTm) in a range of 0.5mm to 1.5mm, a main tooth width

(TWm) in a range of 3.5mm to 5.5mm, a main tooth width bridge (TWb) in a range of 3mm to 5mm, a main slot height (THm) in a range of 11.5mm to 14mm, and each of the plurality of auxiliary winding slots defines, an auxiliary slot opening (SOa), an auxiliary tooth tip thickness (TTa) in a range of 13 mm to 16 mm, an auxiliary tooth width (TWa) in a range of 5.5 mm to 9 mm, an auxiliary opening angle (ANGa) in a range of 20 degrees to 35 degrees, an auxiliary slot height (THa) in a range of 12 mm to 15 mm, wherein an overall outer diameter of the stator assembly is in a range of 125 mm to 150 mm.
An aspect of the present disclosure is that the main slot opening (Som) in a range of 1.4mm to 3.4mm and the main opening angle (ANGm) in a range of 9 degrees to 15 degrees.
Another aspect of the present disclosure is that the auxiliary slot opening (SOa) in a range of 1.4 mm to 2.4 mm.
Yet another aspect of the present disclosure is that each of the plurality of main winding slots and the plurality of auxiliary winding slots are distributed alternately in a circular manner along the outer periphery.
Yet another aspect of the present disclosure is that each main winding slot includes a main opening extending from the outer periphery of the stator lamination, and a pentagonal main cavity extending from the main opening thereof.
Yet another aspect of the present disclosure is that each auxiliary winding slot includes an auxiliary opening extending from the outer periphery of the stator lamination, and a pentagonal auxiliary cavity extending from the auxiliary opening thereof, such that the pentagonal auxiliary cavity is positioned at larger

distance from the outer periphery relative to the pentagonal main cavity. each auxiliary winding slot includes an auxiliary opening extending from the outer periphery of the stator lamination, and a pentagonal auxiliary cavity extending from the auxiliary opening thereof, such that the pentagonal auxiliary cavity is positioned at larger distance from the outer periphery relative to the pentagonal main cavity.
Yet another aspect of the present disclosure is that the plurality of main winding slots and the plurality of auxiliary winding slots allows a plurality of main windings and a plurality of auxiliary windings, respectively, to pass therethrough.
Yet another aspect of the present disclosure is that the plurality of main winding slots are fourteen (14) main winding slots, while the plurality of auxiliary winding slots are fourteen (14) auxiliary winding slots.
Yet another aspect of the present disclosure is that each of the pentagonal main cavity defines five main sides namely a first main side, a second main side, a third main side, a fourth main side and a fifth main side, and four (4) main fillet corners namely a first main fillet corner, a second main fillet corner, a third main fillet corner, and a fourth main fillet corner, such that the first main fillet corner is defined between the first main side and the second main side, the second main fillet corner is defined between the first main side and the third main side, the third main fillet corner is defined between the second main side and the fourth main side, and the fourth main fillet corner is defined between the third main side and the fifth main side.
Yet another aspect of the present disclosure is that each of the pentagonal auxiliary cavity defines five auxiliary sides, namely a first auxiliary side, a second auxiliary side, a third auxiliary side, a fourth auxiliary side and a

fifth auxiliary side, and four (4) auxiliary fillet corners namely a first auxiliary fillet corner, a second auxiliary fillet corner, a third auxiliary fillet corner, and a fourth auxiliary fillet corner, such that the first auxiliary fillet corner is defined between the first auxiliary side and the second auxiliary side, the second auxiliary fillet corner is defined between the first auxiliary side and the third auxiliary side, the third auxiliary fillet corner is defined between the second auxiliary side and the fourth auxiliary side, and the fourth auxiliary fillet corner is defined between the third auxiliary side and the fifth auxiliary side.
Yet another aspect of the present disclosure is that the main slot opening (Som) is an overall width of the main opening, the main tooth tip thickness (TTm) is an overall length of the main opening, the main tooth width (TWm) is shortest distance between either of the second main side or the third main side and the auxiliary opening of an adjacently positioned auxiliary winding slot, the main tooth width bridge (TWb) is either of the distance between the second main fillet corner and the fourth auxiliary side, or the distance between either of the first main fillet corner and the fifth auxiliary side, the main opening angle (ANGm) is either of an angle between the fourth main side and a main imaginary line parallel to the first main side defined between the third main corner and the fourth main corner, or an angle between the fifth main side and the main imaginary line parallel to the first main side defined between the third main corner and the fourth main corner, the main slot height (THm) is a distance between the main imaginary line and the first main side.
Yet another aspect of the present disclosure is that the auxiliary slot opening (SOa) is an overall width of the auxiliary opening, the auxiliary tooth tip thickness (TTa) is an overall length of the auxiliary opening, the auxiliary tooth width (TWa) is shortest distance between either of the second auxiliary side or the third auxiliary side and the third auxiliary side or the second auxiliary side of

an adjacently positioned auxiliary winding slot, the auxiliary opening angle (ANGa) is either of an angle between the fourth auxiliary side and an auxiliary imaginary line parallel to the first auxiliary side defined between the third auxiliary corner and the fourth auxiliary corner, or an angle between the fifth auxiliary side and an auxiliary imaginary line parallel to the first auxiliary side defined between the third auxiliary corner and the fourth auxiliary corner, the auxiliary slot height (THa) is a distance between the auxiliary imaginary line and the first auxiliary side.
BRIEF DESCRIPTION OF DRAWINGS
In order to explain the technical solution in the embodiments of the present application more clearly, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only some embodiments of the application. For those skilled in the art, without any creative work, other drawings can be obtained based on these drawings.
FIG. 1 shows a schematic of a single-phase induction motor employed in a ceiling fan, in accordance with the concepts of the present disclosure.
FIG. 2 shows a top view of a ceiling fan motor lamination disclosing flux lines flow, in accordance with the concepts of the present disclosure.
FIG. 3 shows an enlarged view of a portion of the stator lamination of figure 2, in accordance with the concepts of the present disclosure.
Figure 4a shows a torque waveform generated by the single-phase induction motor at rated power, in accordance with the concepts of the present disclosure.
Figure 4b shows an input and output power waveform the single-phase induction motor at rated power, in accordance with the concepts of the present disclosure.

Figure 4c current waveforms of main winding and the auxiliary winding of single-phase induction motor at rated power, in accordance with the concepts of the present disclosure.
DETAILED DESCRIPTION
In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent, however, that embodiments of the present invention may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address any of the problems discussed above or might address only one of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein. Exemplified embodiments of the present invention are described below, as illustrated in various drawings in which like reference numerals refer to the same parts throughout the different drawings.
Figure 1 shows a schematic of a single-phase induction motor [100] employed in a ceiling fan, in accordance with the concepts of the present disclosure. Although, the concepts of the present disclosure are described as applied to the single-phase induction motor [100] employed in a ceiling fan, it may be obvious to person skilled in the art that the concepts of the present disclosure may also extend to the single-phase induction motor [100] employed in any other household equipment. As is commonly known, the ceiling fan employs an electric motor, for example the single-phase induction motor [100], to rotate an arrangement of fan blades, for generating airflow. An efficiency of the single-phase induction motor [100] is required to be optimized, for improved performance of the ceiling fans. Accordingly, the present disclosure discloses the

single-phase induction motor [100] with improved overall efficiency. The single-phase induction motor [100] includes an inner stator assembly [102] and an outer rotor assembly [104].
The stator assembly [102] is a stationary component that supports a main winding [106] and an auxiliary winding [108], The stator assembly [102] is provided in form of a stack of stator laminations [110], which allows the main winding [106] and the auxiliary winding [108] to pass therethrough. The stator assembly [102] has a recess to receive a shaft [112] therein, which is attached to a top cover [114] of the single-phase induction motor [100]. The stator assembly [102] further defines a number of poles. For example, the stator assembly [102], as disclosed in the present disclosure, defines fourteen (14) poles.
The rotor assembly [104] is squirrel-cage type moving structure attached to the bottom end cover [116] of the single-phase induction motor [100]. The rotor assembly [104] includes a stack of rotor lamination [118], which carries rotor bars [120] skewed at an angle relative to the rotor lamination [118].
In operation, the combination of the main winding [106] and the auxiliary winding [108], are excited with a single-phase alternating current. This creates a magnetomotive force (MMF) in an air-gap between the stator assembly [102] and the rotor assembly [104]. An electromotive force (EMF) further induced in the rotor bars [120] of the rotor assembly [104], which creates an MMF opposing the induced EMF. Thus, two MMFs interact to produce the torque, for rotating the single-phase induction motor [100].
Furthermore, figure 2 shows a top view of a ceiling fan motor lamination comprising the stator lamination (110) and the rotor lamination (118) disclosing flux lines flow, in accordance with the concepts of the present disclosure. Figure 3 shows an enlarged view of a portion of the stator lamination [110], in accordance with the concepts of the present disclosure. Figure 2 and figure3 should be referred to in conjunction with each other, in order to clearly understand the concepts of the present disclosure. Although, a structure and

arrangement of a singular laminations [110] is described herein, similar structure and arrangement of remaining of the stack of stator lamination [110] may be contemplated. The stack of stator laminations [110] is a disc-shaped structure defining at least a plurality of main winding slots [202] and a plurality of auxiliary winding slots [204] positioned at different radial lengths, such that the plurality of auxiliary winding slots [204] are at deeper radial level than the plurality of main winding slots [202], relative to an outer periphery [206] of the stator lamination [110]. Further, the plurality of main winding slots [202] and the plurality of auxiliary winding slots [204] are distributed alternatively in a circular manner along the periphery. The plurality of main winding slots [202] are provided to route therethrough the main winding [106], while the plurality of auxiliary winding slots [204] are provided to route therethrough the auxiliary winding [108]. In an embodiment, the stator lamination [110] defines fourteen (14) main winding slots [202] and fourteen (14) auxiliary winding slots [204] radially distributed in a circular manner on the stator lamination [110], such that the fourteen (14) auxiliary winding slots [204] are at deeper radial level than the fourteen (14) main winding slots [202], relative to the outer periphery [206] of the stator lamination [110], and thus defines fourteen (14) poles thereof.
A dimensional arrangement of the one of the plurality of main winding slots [202], will now be explained in details. Similar dimensional arrangement of the remaining of the plurality of main winding slots [202], may be envisioned. Each of the plurality of main winding slots [202] includes a main opening extending from the outer periphery [206] of the stator lamination and a pentagonal main cavity extending from the main opening thereof. The pentagonal cavity having four (4) connected corners and one (1) open corner, such that the open corner opens up at the periphery [206] of the stator lamination [110] via the main opening [208].
In a preferred embodiment, the main winding slots [202] includes five sides, namely a first main side [202a], a second main side [202b], a third main

side [202c], a fourth main side [202d], and a fifth main side [202e]. The main winding slots [202] is defined, such that the first main side [202a] is parallel to a tangent at an interface of its main opening [208]; the second main side [202b] extend at an angle from the first main side [202a]; the third main side [202c] extend at an angle from the first main side [202a], such that the third main side [202c] and the second main side [202b] diverges away from each other; the fourth main side [202d] extend at an angle from the second main side [202b], and the fifth main side [202e] extend at an angle from the third main side [202c], such that the fifth main side [202e] and the fourth main side [202d] converges together at a fifth open corner.
Notably, a first fillet corner is defined between the first main side [202a] and the second main side [202b], a second fillet corner is defined between the first main side [202a] and the third main side [202c], a third fillet corner is defined between the second main side [202b] and the fourth main side [202d], a fourth fillet corner is defined between the third main side [202c] and the fifth main side [202e], while an open corner is defined between the fourth main side [202d] and the fifth main side [202e].
With such structure and arrangement, the main winding slots [202] defines: a main slot opening SOm is a width of the main opening [208]; a main tooth tip thickness TTm is a length of the main opening [208]; a main tooth width TWm is a shortest distance between either of the second main side [202b] or the third main side [202c], and an auxiliary opening [210] of adjacently positioned auxiliary winding slot [204]; a main tooth width bridge TWb is a distance between one of the second fillet corner and a fourth auxiliary side [204d] of the auxiliary winding slots [204] or the distance between the first fillet corner and a fifth auxiliary side [204e] of the auxiliary winding slot [204]; a main opening angle ANGm is an angle between the fourth main side [202d] and an main imaginary line thereof, or an angle between the fifth main side [202e] And the main imaginary line. The main imaginary line parallel to the first main side [202a] and

defined between the third main fillet corner and the fourth main fillet corner, a main slot height THm that is a distance between the main imaginary line and the first main side [202a].
In the present embodiment wherein an overall outer diameter of the stator lamination is in a range of 125 mm to 150 mm, the main slot opening SOm is kept in a range of 1.4 mm to 2.4 mm, the main tooth tip thickness TTm is kept in a range of 0.5 mm to 1.5 mm, the main tooth width TWm is kept in a range of 3.5 mm to 5.5 mm, the main tooth width bridge TWb is kept in a range of 3 mm to 5 mm, the main opening angle ANGm is kept in a range of 9 degrees to 15 degrees, the main slot height THm is kept in a range of 11.5 mm to 14 mm.
A dimensional arrangement of the one of the plurality of auxiliary winding slots [204], will now be explained in details. Similar dimensional arrangement of the remaining of the plurality of main auxiliary slots [204], may be envisioned. The auxiliary winding slots [204] includes an auxiliary opening [210] extending from the outer periphery [206] of the stack of stator lamination [110] and an auxiliary pentagonal cavity being positioned at a larger distance from the outer periphery [206] relative to the pentagonal main cavity. The auxiliary pentagonal cavity having four (4) connected corners and one (1) open corner, such that the open corner opens up at the outer periphery [206] of the stator lamination [110] via the auxiliary opening [208].
In a preferred embodiment,, the auxiliary winding slots [202] includes five sides, namely a first auxiliary side [204a], a second auxiliary side [204b], a third auxiliary side [204b], a fourth auxiliary side [204d], and a fifth auxiliary side [204e]. The auxiliary winding slots [202] is defined, such that the first auxiliary side [204a] is parallel to a tangent at an interface of its auxiliary opening [210]; the second auxiliary side [204b] extend at an angle from the first auxiliary side [204a]; the third auxiliary side [204b] extend at an angle from the first auxiliary side [204a], such that the third auxiliary side [204b] and the second auxiliary side

[204b] diverges away from each other; the fourth auxiliary side [204d] extend at an angle from the second auxiliary side [204b], and the fifth auxiliary side [204e] extend at an angle from the third auxiliary side [204b], such that the fifth auxiliary side [204e] and the fourth auxiliary side [204d] converges together at a fifth open corner.
Notably, a first fillet auxiliary corner is defined between the first auxiliary side [204a] and the second auxiliary side [204b], a second fillet auxiliary corner is defined between the first auxiliary side [204a] and the third auxiliary side [204b], a third auxiliary corner is defined between the second auxiliary side [204b] and the fourth auxiliary side [204d], a fourth fillet auxiliary corner is defined between the third auxiliary side [204c] and the fifth auxiliary side [204e], while an open auxiliary corner is defined between the fourth auxiliary side [204d] and the fifth auxiliary side [204e]. With such structure and arrangement, the auxiliary winding slots [202] defines: an auxiliary slot opening SOa that is a overall width of the auxiliary opening [210]; an auxiliary tooth tip thickness TTa that is a length of the auxiliary opening [210]; an auxiliary tooth width TWa is one of a shortest distance between the second auxiliary side [204b] and the third auxiliary side [204c] of an adjacently positioned auxiliary winding slot [204], or a shortest distance between the third auxiliary side [204c] and the second auxiliary side [202b] of an adjacently positioned auxiliary winding slot [204], an auxiliary opening angle ANGa is either of an angle between the fourth auxiliary side [204d] and an auxiliary imaginary auxiliary line thereof or an angle between the fifth auxiliary corner and the imaginary auxiliary line thereof. The auxiliary line parallel to the first auxiliary side [204a] and defined between the third auxiliary corner and the fourth auxiliary corner; an auxiliary slot height THa that is a distance between the auxiliary imaginary line and the first auxiliary side [204a].
In the present embodiment wherein an overall outer diameter of the stator lamination is in a range of 125 mm to 150 mm, the auxiliary slot opening SOa is kept in a range of 1.4 mm to 2.4 mm, the auxiliary tooth tip thickness TTa

is kept in a range of 13 mm to 16 mm, the auxiliary tooth width TWa is kept in a range of 5.5 mm to 9 mm, a main opening angle ANGa is kept in a range of 20 degrees to 35 degrees, a main slot height THa is kept in a range of 12 mm to 15 mm.
With such defined specifications of the plurality of main winding slots [202] and the plurality of auxiliary winding slots [204], core losses and copper losses are optimized, and thus an improved overall efficiency of the single-phase induction motor [100] is achieved. In particular, such dimensional optimization of plurality of main winding slots [202] and the plurality of auxiliary winding slots [204] of the stator disclosed stator lamination [110], optimizes the area of the slots to allow maximum amount of windings [104, 106] while not majorly effecting the fluxes, and therefore the copper losses and core losses through the stator lamination [110] are optimized. This results in improved efficiency of the single-phase induction motor [100] of the ceiling fan, thereby enhancing overall performance of the ceiling fan thereof. Further, dimensional optimization results in achieving an air delivery rate of the induction motor above 200m3 and a service value above 6m3/min/watt. Thereby, achieving a five (5) star rating as per IS 374:2019 and IS 302-2-80:2017.
Figure 4a shows a torque waveform generated by the single-phase induction motor [100] at rated power, in accordance with the concepts of the present disclosure. Figure 4b shows an input and output power waveform the single-phase induction motor [100] at rated power, in accordance with the concepts of the present disclosure. Figure 4c current waveforms of main winding and the auxiliary winding of single-phase induction motor [100] at rated power, in accordance with the concepts of the present disclosure. The graphical representation of the figures 4a-c evidenced the increase in efficiency of the single-phase induction motor [100].
While the preferred embodiments of the present invention have been

described hereinabove, it should be understood that various changes, adaptations, and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims. It will be obvious to a person skilled in the art that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.
List of Components
100 - Single-phase Induction Motor
102 - Inner Stator Assembly
104 - Outer Rotor Assembly
106 – Main Winding
108 - Auxiliary Winding
110 - Stack of Stator Laminations
112 - Shaft
114 - Top cover
116 – Bottom End Cover
118 - Stack of Rotor Lamination
120 - Rotor Bars
202 – Main winding slots
202a -First main side
202b – Second main side
202c – Third main side
202d – Fourth main side
202e – Fifth main side
204 – Awind slots
204a -First auxiliary side
204b – Second auxiliary side

204c – Third auxiliary side 204d – Fourth auxiliary side 204e – Fifth auxiliary side 206 – Outer periphery 208 – Main opening 210 – Auxiliary opening

I/We Claim
1. A stator assembly [102] for an induction motor [100] employed in a
ceiling fan, the stator assembly [102] comprising:
- a stack of stator laminations [110], each stator laminations [110]
defining a plurality of main winding slots [202] and a plurality of
auxiliary winding slots [204] at pre-defined radial lengths extending
radially inwards from an outer periphery, wherein each of the plurality
of main winding slots [202] defines:
a main slot opening (Som)
a main opening angle
a main tooth tip thickness (TTm) in a range of 0.5mm to 1.5mm
a main tooth width (TWm) in a range of 3.5mm to 5.5mm
a main tooth width bridge (TWb) in a range of 3mm to 5mm
a main slot height (THm) in a range of 11.5mm to 14mm and
- each of the plurality of auxiliary winding slots [204] defines
an auxiliary slot opening (SOa)
an auxiliary tooth tip thickness (TTa) in a range of 13 mm to 16
mm
an auxiliary tooth width (TWa) in a range of 5.5 mm to 9 mm
an auxiliary opening angle (ANGa) in a range of 20 degrees to 35
degrees
an auxiliary slot height (THa) in a range of 12 mm to 15 mm,
- an overall outer diameter of the stator assembly is in a range of 125
mm to 150 mm.
2. The stator assembly as claimed in claim 1, wherein the main slot opening
(Som) in a range of 1.4mm to 3.4mm and the main opening angle (ANGm)
in a range of 9 degrees to 15 degrees.

3. The stator assembly as claimed in claim 1, wherein the auxiliary slot opening (SOa) in a range of 1.4 mm to 2.4 mm.
4. The stator assembly as claimed in claim 1, wherein each of the plurality of main winding slots [202] and the plurality of auxiliary winding slots [204] are distributed alternately in a circular manner along the outer periphery.
5. The stator assembly as claimed in claim 1, wherein each main winding slot [202] includes a main opening extending from the outer periphery [206] of the stator lamination, and a pentagonal main cavity extending from the main opening thereof.
6. The stator assembly as claimed in claims 1 to 3, wherein each auxiliary winding slot [204] includes an auxiliary opening extending from the outer periphery [206] of the stator lamination [110], and a pentagonal auxiliary cavity extending from the auxiliary opening thereof, such that the pentagonal auxiliary cavity is positioned at larger distance from the outer periphery [206] relative to the pentagonal main cavity.
7. The stator assembly as claimed in claim 1, wherein the plurality of main winding slots [202] and the plurality of auxiliary winding slots [204] allows a plurality of main windings [106] and a plurality of auxiliary windings [108], respectively, to pass therethrough.
8. The stator assembly as claimed in claim 1, wherein the plurality of main winding slots [202] are fourteen (14) main winding slots [202], while the plurality of auxiliary winding slots [204] are fourteen (14) auxiliary winding slots [108].
9. The stator assembly as claimed in claim 3, wherein each of the pentagonal main cavity defines five main sides namely a first main side [202a], a second main side [202b], a third main side [202c], a fourth main

side [202d] and a fifth main side [202e], and four (4) main fillet corners namely a first main fillet corner, a second main fillet corner, a third main fillet corner, and a fourth main fillet corner, such that the first main fillet corner is defined between the first main side [202a] and the second main side [202b], the second main fillet corner is defined between the first main side [202a] and the third main side [202c], the third main fillet corner is defined between the second main side [202b] and the fourth main side [202d], and the fourth main fillet corner is defined between the third main side [202c] and the fifth main side [202e].
10. The stator assembly as claimed in claim 4, wherein each of the pentagonal auxiliary cavity defines five auxiliary sides, namely a first auxiliary side [204a], a second auxiliary side [204b], a third auxiliary side [204c], a fourth auxiliary side [204d] and a fifth auxiliary side [204e], and four (4) auxiliary fillet corners namely a first fillet auxiliary corner, a second fillet auxiliary corner, a third fillet auxiliary corner, and a fourth fillet auxiliary corner, such that the first fillet auxiliary corner is defined between the first auxiliary side [204a] and the second auxiliary side [204b], the second fillet auxiliary corner is defined between the first auxiliary side [204a] and the third auxiliary side [204c], the third fillet auxiliary corner is defined between the second auxiliary side [204b] and the fourth auxiliary side [204d], and the fourth fillet auxiliary corner is defined between the third auxiliary side [204c] and the fifth auxiliary side [204e].
11. The stator assembly as claimed in claims 1-8, wherein,

- the main slot opening (Som) is an overall width of the main opening,
- the main tooth tip thickness (TTm) is an overall length of the main opening,

- the main tooth width (TWm) is shortest distance between either of the second main side [202b] or the third main side [202c] and the auxiliary opening of an adjacently positioned auxiliary winding slot [204],
- the main tooth width bridge (TWb) is either of the distance between the second main fillet corner and the fourth auxiliary side [204d], or the distance between either of the first main fillet corner and the fifth auxiliary side,
- the main opening angle (ANGm) is either of an angle between the fourth main side [202d] and a main imaginary line parallel to the first main side [202a] defined between the third main corner [202c] and the fourth main corner [202d], or an angle between the fifth main side [202e] and the main imaginary line parallel to the first main side [202a] defined between the third main corner and the fourth main corner,
- the main slot height (THm) is a distance between the main imaginary line and the first main side [202a].
12. The stator assembly as claimed in claims 1-8, wherein,
- the auxiliary slot opening (SOa) is an overall width of the auxiliary opening,
- the auxiliary tooth tip thickness (TTa) is an overall length of the auxiliary opening,
- the auxiliary tooth width (TWa) is one of a shortest distance between the second auxiliary side [204b] and the third auxiliary side [204c] of an adjacently positioned auxiliary winding slot [204], or the shortest distance between the third auxiliary side [204c] and the second auxiliary side [202b] of an adjacently positioned auxiliary winding slot [204],

- the auxiliary opening angle (ANGa) is either of an angle between the fourth auxiliary side [204d] and an auxiliary imaginary line parallel to the first auxiliary side [204a] defined between the third auxiliary corner and the fourth auxiliary corner, or an angle between the fifth auxiliary side [204e] and an auxiliary imaginary line parallel to the first auxiliary side [204a] defined between the third auxiliary corner and the fourth auxiliary corner,
- the auxiliary slot height (THa) is a distance between the auxiliary imaginary line and the first auxiliary side [204a].
13. The stator assembly as claimed in claim, wherein an air delivery rate of the induction motor is in the range of 200 to 240m3 and a service value is in a range of 5 to 8 m3/min/watt.