Description:FIELD OF THE INVENTION
[001] The present invention generally relates to machines. More particularly, the present invention relates to provision of a rotary electrical machine.

BACKGROUND OF THE INVENTION
[002] Generally, in conventional motor assembly, a stator and a rotor are provided. The stator is the stationary part of the motor assembly, and the rotor is the rotating part of the motor assembly. The rotor is configured to work in conjunction with the stator to transmit the power of an electrical machine. The stator and the rotor are made by stacking of plurality of metal lamination sheets. Further each of the stator lamination sheets, and the rotor lamination sheets are provided with an interlock. The interlock facilitates in providing grip and rigidity to the lamination sheets, thereby holding the stator lamination sheets and the rotor lamination sheets together to form the stator and the rotor.
[003] Further, the interlock is disposed in the stator back iron in an outer diameter of the stator assembly. However, such a disposition of the interlock makes it easily detachable due to centripetal force acting on the interlock during the running condition of the motor assembly. Furthermore, a stator tooth is provided to hold the stator lamination sheets. However, there are chances of loosening of the stator tooth from each of the lamination sheets due to the location of the interlock in the stator back iron only and hence may loosen the stacking of the stator.
[004] Conventionally, welding and cleating of the lamination sheets is also used, however the same is time consuming and involves a lot of complexity during the assembly process. Further, the welding and the cleating process also leads to the overall drop in the motor assembly performance. This is particularly due to misalignment during the welding process. Furthermore, in another conventional design, the interlock is disposed only on the stator tooth. The disposition of the interlock on the stator tooth ensures a rigid attachment of the stator tooth with each other. However, this disposition leads to the loosening of the lamination sheets from the stator back iron due to the centrifugal force acting on the lamination sheets during the running condition of the motor assembly.
[005] Furthermore, the disposition of the interlock on the stator tooth leads to a low torque production during the starting condition of the motor assembly. This leads to an overall reduced motor performance. Also, the optimum output power is not achieved during the starting condition of the motor assembly and during the maximum speed running condition of the motor assembly. Therefore, the disposition of the interlock is required in such a manner so as to overcome the problems related to output power and efficiency of the motor performance. The conventional disposition of the interlock leads to inefficient performance of the motor assembly and also provides difficulty in the assembly of the lamination sheets.
[006] Thus, there is a need in the art for a rotary electrical machine, which addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[007] In one aspect, the present invention relates to a rotary electrical machine. The rotary electrical machine includes a rotor having a plurality of magnets. The rotary electrical machine has a stator assembly, and the rotor is configured to be rotatably engaged with the stator assembly. The stator assembly has one or more stator sheets interlocked to each other. Each stator sheet has a plurality of stator teeth configured to receive one or more stator coils. Each stator sheet further has a stator yoke and one or more interlock tabs. The plurality of stator teeth extends from the stator yoke. The one or more interlock tabs is configured to interlock the one or more stator sheets to each other. Furthermore, at least a first part of each interlock tab is provided on the stator yoke and at least a second part of each interlock tab is provided on one of the stator teeth.
[008] In an embodiment of the invention, the stator assembly is provided radially outward from the rotor, and the plurality of stator teeth extend radially inward from the stator yoke.
[009] In a further embodiment of the invention, each stator sheet has a planar shape, and the one or more stator sheets are laminated and stacked on top of each other to form the stator assembly.
[010] In a further embodiment of the invention, each interlock tab extends in a radial direction of the stator sheet.
[011] In a further embodiment of the invention, each interlock tab has a notch extending in an axial direction of the stator sheet, thereby defining a recess on a top face of the stator sheet and a protrusion on a bottom face of the stator sheet.
[012] In a further embodiment of the invention, the protrusion on the bottom face of the stator sheet is configured to engage with the recess on the top face of another stator sheet, thereby interlocking the one or more stator sheets.
[013] In a further embodiment of the invention, the notch has a depth ranging between 0.2mm and 0.8mm, and each notch has a length ranging between 1mm to 3.5 mm.
[014] In a further embodiment of the invention, each interlock tab is provided on alternate stator teeth of the stator sheet.

BRIEF DESCRIPTION OF THE DRAWINGS
[015] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a perspective view of a rotary electrical machine, in accordance with an embodiment of the present invention.
Figure 2 illustrates a perspective view of a stator assembly, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[016] The present invention generally relates to machines. More particularly, the present invention relates to provision of a rotary electrical machine.
[017] Figure 1 illustrates a perspective view of a rotary electrical machine 100, in accordance with an embodiment of the present invention. In an embodiment of the present invention, the rotary electrical machine includes motors, generators, alternators, and the like. The rotary electrical machine 100 is provided with a rotor 110 and a stator assembly 120. The rotor 110 is the rotating part of the rotary electrical machine 100 and includes a plurality of magnets 112. The plurality of magnets 112 are configured to produce a constant magnetic field. The rotor 110 is configured to be rotatably engaged with the stator assembly 120. The stator assembly 120 is the stationary part of the rotary electrical machine 100 and is provided radially outward from the rotor 110. Also, the rotary electrical machine 100 is encased inside a motor housing during the assembly of the rotor 110 and a stator assembly 120.
[018] The stator assembly 120 is provided with one or more stator sheets 122. The one or more stator sheets 122 are interlocked with each other. In an embodiment, the one or more stator sheets 122 are laminated and stacked on top of each other to form the stator assembly 120. The present invention allows the one or more stator sheets 122 to be interlocked so as to increase the overall performance and the efficiency of the rotary electrical machine 100.
[019] Figure 2 illustrates a perspective view of a stator assembly, in accordance with an embodiment of the present invention. As depicted, each stator sheet 122A of the one or more stator sheets 122 includes a plurality of stator teeth 124 and a stator yoke 126. The stator teeth 124 and the stator yoke helps in holding the one or more stator sheets 122 together and provides the additional grip so as to reduce the loosening of the stator sheets 122 during the working condition of the rotary electrical machine 100. In an embodiment, each stator sheet 122A has a planar shape. The plurality of stator teeth 124 is configured to receive one or more stator coils. The plurality of stator teeth 124 further extends from the stator yoke 126. Also, the plurality of stator teeth 124 extend radially inward from the stator yoke 126.
[020] Each stator sheet 122A of the one or more stator sheets 122 further includes one or more interlock tabs 128 for interlocking the one or more stator sheets 122 to each other. The one or more interlock tabs 128 are provided with at least a first part and at least a second part. The first part of each interlock tab 128 is provided on the stator yoke 126 and the second part of each interlock tab 128 is provided on one of the stator teeth 124. Therefore, the one or more interlock tabs 128 of the present invention allows the stator sheets 122 to be interlocked with each other and hence, makes the assembly easier and simple.
[021] In an embodiment, each interlock tab 128 is provided on alternate stator teeth 124 of the stator sheet 122A. In yet another embodiment of the present disclosure, each interlock tab 128 extends in a radial direction of the stator sheet 122A.
[022] In an embodiment of the present invention, the one or more interlock tabs 128 are disposed between the stator teeth 124 and the stator yoke 126. Also, the one or more interlock tabs 128 are oriented in a vertical position. The one or more interlock tabs 128 are provided radially opposite to the plurality of magnets 112 of the rotor 110.
[023] In yet another embodiment of the present invention, each interlock tab 128 includes a notch extending in an axial direction of the stator sheet 122A, thereby defining a recess on a top face of the stator sheet 122A and a protrusion on a bottom face of the stator sheet 122A. The notch helps in further enhancing the efficiency of the rotary electrical machine 100. Further, the protrusion on the bottom face of the stator sheet 122A is configured to engage with the recess on the top face of another stator sheet 122A, thereby interlocking the one or more stator sheets 122. In an embodiment, the notch has a depth ranging between 0.2 mm and 0.8 mm, and each notch has a length ranging between 1 mm to 3.5 mm. The notch provided in the interlock tab reduces the losses and leads to an overall improved performance and efficiency of the rotary electrical machine 100.
[024] Advantageously, the present invention provides for a rotary electrical machine with the one or more interlock tabs to hold the stator sheets with each other. The disposition of the one or more interlock tabs on the stator yoke and the stator teeth prevents the loosening of the stator sheets, thereby improving the overall performance and the efficiency of the rotary electrical machine. Such a disposition of the one or more interlock tabs negates the effect of the centrifugal force and the centripetal force acting on the one or more interlock tabs during the running condition of the motor assembly, thereby preventing the loosening of the stator sheets. The present invention further provides the ease of the assembly of the stator sheets of the rotary electrical machine.
[025] The present invention allows for better performance and durability of the rotary electrical machine and eliminates the overall complexity associated with the interlocking of the stator sheets. Further, the present invention eliminates the welding and cleating process and thereby, reducing the overall manufacturing costs.
[026] Further, by provision of the one or more interlock tabs, the interlocking of the stator sheets with each other is made easier and reduces assembly complexity. In addition, the manufacturing of the rotary electrical machine has been simplified. This leads to cost saving leading to better overall efficiency of the rotary electrical machine.
[027] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

List of Reference Numerals
100: Rotary Electrical Machine
110: Rotor
112: Magnets
120: Stator Assembly
122: One or More Stator Sheets
122A: Stator Sheet
124: Stator Teeth
126: Stator Yoke
128: Interlock Tab
, Claims:1. A rotary electrical machine (100), comprising:
a rotor (110), the rotor (110) having a plurality of magnets (112); and
a stator assembly (120), wherein the rotor (110) is configured to be rotatably engaged with the stator assembly (120), the stator assembly (120) comprising one or more stator sheets (122) interlocked to each other, each stator sheet (122A) comprising:
a plurality of stator teeth (124), the plurality of stator teeth (124) configured to receive one or more stator coils;
a stator yoke (126), the plurality of stator teeth (124) extending from the stator yoke (126); and
one or more interlock tabs (128) for interlocking the one or more stator sheets (122) to each other, at least a first part of each interlock tab (128) being provided on the stator yoke (126) and at least a second part of each interlock tab (128) being provided on one of the stator teeth (124).

2. The rotary electrical machine (100) as claimed in claim 1, wherein the stator assembly (120) is provided radially outward from the rotor (110), and the plurality of stator teeth (124) extend radially inward from the stator yoke (126).

3. The rotary electrical machine (100) as claimed in claim 1, wherein each stator sheet (122A) has a planar shape, and the one or more stator sheets (122) are laminated and stacked on top of each other to form the stator assembly (120).

4. The rotary electrical machine (100) as claimed in claim 1, wherein each interlock tab (128) extends in a radial direction of the stator sheet (122A).

5. The rotary electrical machine (100) as claimed in claim 1, wherein each interlock tab (128) comprises a notch extending in an axial direction of the stator sheet (122A), thereby defining a recess on a top face of the stator sheet (122A) and a protrusion on a bottom face of the stator sheet (122A).

6. The rotary electrical machine (100) as claimed in claim 5, wherein the protrusion on the bottom face of the stator sheet (122A) is configured to engage with the recess on the top face of another stator sheet (122A), thereby interlocking the one or more stator sheets (122).

7. The rotary electrical machine (100) as claimed in claim 5, wherein the notch has a depth ranging between 0.2mm and 0.8mm, and each notch has a length ranging between 1mm to 3.5mm.

8. The rotary electrical machine (100) as claimed in claim 1, wherein each interlock tab (128) is provided on alternate stator teeth (124) of the stator sheet (122A).