Claims:We claim:
1. A rotor assembly (100) for reducing a stator winding temperature of a magneto, the rotor assembly (100) comprising:
a rotor cup (102);
a fan (108) rivetted into the rotor cup (102), wherein the fan (108) comprises a plurality of fins (118) integrated on the fan (108); and
at least two magnets (306) mounted inside the rotor cup (102) on the fan (108).

2. The rotor assembly as claimed in claim 1, wherein the fan (108) comprises:
at least two magnet separators (204) for separating at least two magnets (306); and
a set of holes (116) to direct hot air out of the magneto.

3. The rotor assembly as claimed in claim 1, wherein the rotor assembly (100) further comprises:
a rotor boss (104); and
a magnet case (308) for holding the at least two magnets (306) in a fixed position.

4. The rotor assembly as claimed in claim 1, wherein the plurality of fins (118) rotates along with the rotor cup (102) to direct hot air out of the magneto.

5. A rotor assembly (100) for reducing a stator winding temperature of a magneto, the rotor assembly (100) comprising:
a rotor cup (102);
a rotor boss (104) extending outward from a first surface of the rotor cup (102);
a fan (108) mounted on the rotor cup (102), wherein the fan (108) further comprises a plurality of fins (118) mounted on a top surface of the fan (108);
at least two magnet separators (204) mounted on the periphery of the fan (108); and
at least two magnets (306) mounted on the rotor cup (102).

6. The rotor assembly (100) as claimed in claim 5, further comprises:
a plurality of elements (106) extending outwards from the surface of the rotor cup (102); and
a first hole (110), a first set of holes (112), a second set of holes (114), and a third set of holes (116).

7. The rotor assembly (100) as claimed in claim 5, wherein the plurality of fins (118) have at least one geometric shape, and wherein the at least one geometric shape comprises a curved geometric shape.

8. The rotor assembly (100) as claimed in claim 5, wherein the plurality of fins (118) is positioned adjacent to a hole from the third set of holes (116).

9. The rotor assembly (100) as claimed in claim 5, wherein the at least two magnet (306) are positioned circumferentially on a wall (312) of the rotor cup (302).

10. The rotor assembly (100) as claimed in claim 5, wherein the at least two magnets (306) is sandwiched between the wall (312) on a first side and a magnet case (308) on a second side.

Dated this 02nd Day of November 2021

Priyank Gupta
Agent for the Applicant
IN/PA-1454
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION

(See Section 10 and Rule 13)

Title of invention:
MEANS FOR REDUCING STATOR WINDING TEMPERATURE

Varroc Engineering Limited.
An Indian entity having address as:
L-4, MIDC Waluj,
Aurangabad-431136,
Maharashtra, India

The following specification describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
The present subject matter describes herein, relates to automobile. More specifically, the present subject matter relates to a means for reducing stator winding temperature.

BACKGROUND
The subject matter discussed in the background section should not be assumed to be prior art merely because of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.

Presently, permanent magnet synchronous machines (PMSM) are used as magneto for generating power in automotive applications. An increase in the RPM speed of a crank shaft results in increase in output power and increase in the amount of heat generated within the magneto. The heat generated within the magneto leads to demagnetization effect, thereby reducing the deliverable output power and performance of the magneto.

Several existing solutions fall short in reducing the heat generated inside the magneto and improving the circulation to remove the hot air present inside the magneto. An exemplary prior art discloses an electric magneto having a rotor and a stator. The stator may further include a plurality of coil windings. The rotor as disclosed is further configured to rotate about a rotational axis with a plurality of permanent magnets positioned about the rotational axis. The plurality of permanent magnets are further arranged on a circumference of the rotor. A magnetically non-effective zone is created in a central region of the rotor i.e., a zone not affected by the magnetic flux. The prior art further discloses at least one opening that extends substantially in an axial direction in the magnetically non-effective zone of the rotor to form an air flow path through the rotor. A fan externally mounted on the rotor is configured to move with the rotor so as to generate an airflow along the airflow path through the at least one opening of the rotor. However, the externally mounted fan does not provide effective cooling of magneto.

Thus, there exist a need in the art to provide a system and a mechanism which overcome the above-mentioned problems to reduce the amount of heat generated inside the magneto and to maintain the performance and output power of the magneto. Further, there is also a long felt need to enable a light weighted stator winding cooling means.

SUMMARY
This summary is provided to introduce concepts related to a means of reducing temperature of stator winding of rotor of a vehicle, and the concepts are further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.

In one implementation, a rotor assembly (100) for reducing a stator winding temperature of a magneto is disclosed. The rotor assembly (100) may comprise a rotor cup (102). A fan (108) rivetted into the rotor cup (102). The fan (108) further comprises a plurality of fins (118) integrated on the fan (108). The rotor assembly (100) further comprises at least two magnets (306) mounted inside the rotor cup (102) on the fan (108).

In another implementation a rotor assembly (100) for reducing a stator winding temperature of a magneto comprises a rotor cup (102). Further, a rotor boss (104) may extend outward from a first surface of the rotor cup (102). The rotor assembly (100) may further comprise a fan (108) mounted on the rotor cup (102), wherein the fan (108) further comprises a plurality of fins (118) mounted on a top surface of the fan (108). Further, at least two magnet separators (204) may be mounted on the periphery of the fan (108). The rotor assembly (100) may further comprise at least two magnets (306), mounted on the fan (108).

BRIEF DESCRIPTION OF DRAWINGS
The detailed description is described with reference to the accompanying Figures. The same numbers are used throughout the drawings to refer like features and components.

Figure 1 illustrates a schematic diagram of a rotor assembly, in accordance with an embodiment of the present subject matter.

Figure 2 illustrates a fan, in accordance with an embodiment of the present subject matter.

Figure 3 illustrates another exemplary embodiment of a rotor assembly, in accordance with the present subject matter.

DETAILED DESCRIPTION
Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in an embodiment” in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

The present disclosure discloses an apparatus, a system and a means for reducing the temperature in a stator and a stator winding. In accordance with an exemplary embodiment a magneto may comprise a rotor assembly, and a stator assembly. The stator assembly may further comprise a stator and a plurality of coil/windings wrapped around the stator.

In accordance with the exemplary embodiment, the stator assembly may be mounted on a rotor shaft. The rotor shaft may further be coupled to a rotor boss. The rotor boss may be integrated or provided on a surface of a rotor cup. The rotor cup may further comprise a fan is directly mounted on the surface of the rotor cup. The fan may further comprise a plurality of fins, at least two separators, and a plurality of holes. The fan may further comprise a centrally positioned hole configured to fit around the rotor boss. The rotor boss and a plurality of rivets/fasteners enable the mounting of the fan on the rotor cup. The plurality of holes on the fan may further enable additional heat dissipation and place for rivets/fasteners.

Figure 1, illustrates a schematic diagram of a rotor assembly in accordance with an embodiment of the present subject matter. The rotor assembly 100 as disclosed in the exemplary embodiment may comprise a rotor cup 102. The rotor cup 102 may further comprise a rotor boss 104. The rotor boss 104 may extend outward from a first surface of the rotor cup 102. The rotor boss 104 may further be configured to engage with a rotor shaft (not Shown), and further the rotor shaft may be coupled to a fly wheel. The fly wheel may be further coupled to an engine.

In accordance with the exemplary embodiment, the rotor cup 102 may further comprise a plurality of elements 106 extending outwards from the surface of the rotor cup 102. The plurality of elements 106 and the rotor boss 104 may be further configured to engage with a fan 108 mounted on the rotor cup 102. The fan 108 may further comprise a first hole 110, a first set of holes 112, a second set of holes 114, and a third set of holes 116.

The first hole 110 may be configured to engage with the rotor boss 104. The plurality of elements 106 that are peripherally arranged adjacent to the rotor boss 104 may engage with the first set of holes 112 of the fan 108. The second set of holes 114 provided on the fan 108 may be configured to receive rivets so as to be fastened with the rotor cup 102. The rotor cup 102 may further comprise plurality of holes having shape similar to the third set of holes 116 on the fan 108, and positioned to overlap with each other.

The fan 108 may further comprise a plurality of magnets mounted on a top surface of the fan 108. The top surface may be a surface provided on opposite side of another surface engaged with the surface of the rotor cup 102. The top surface of the fan 108 may also comprise a plurality of fins 118. The plurality of fins 118 may be configured to circulate air, and give a direction to the air to flow over a stator and stator winding mounted on the rotor shaft. The air may flow from the holes and the plurality of fins 118 may provide direction and turbulence so as to enable the air to flow over the stator surface and remove additional heat to reduce the temperature.

Referring to Figure 2, illustrates a fan, in accordance with an embodiment of the present subject matter. The fan 108, as disclosed in the present exemplary embodiment comprises a top surface 202. The top surface 202 may be surface provided on a side opposite to a bottom surface. The bottom surface may be engaged with a surface of a rotor cup.

In accordance with the exemplary embodiment the top surface 202 of the fan may comprise a first hole 110, a first set of holes 112, a second set of holes 114, and a third set of holes 116. The various holes on the top surface of the fan 108 may be configured to engage with the rotor cup to restrict any relative motion between them and further to channelise the air flowing through openings/holes in the rotor cup.

The fan 108 may further comprise a plurality of fins 118 extending away or outwards from the top surface 202. The plurality of fins 118 may have straight geometric shape or curved geometric shape in order to provide direction for air flow.

The plurality of fins 118 may be provided such that each fin 118 from the plurality of fins 118 is positioned adjacent to a hole from the third set of holes 116. The air entering of the third set of holes and the complimentary openings on the rotor cup is made to flow over the plurality of 118, and thus providing a direction that enables the flow over a stator and stator winding.

The plurality fins 118 may further comprise at least two magnet separators 204. The at least two magnet separators 204, may be mounted on the top surface. The at least two magnet separators 204 may further be positioned or mounted on the periphery of the fan 108. The at least two magnet separators 204 may be configured to hold and provide a small gap between magnets arranged circumferentially on the periphery of the fan 108.

Figure 3 illustrates another exemplary embodiment of a rotor assembly, in accordance with the present subject matter. The rotor assembly 300 may comprise a rotor cup 302, a fan 304, at least two magnets 306, and a magnet case 308. In accordance with the exemplary embodiment the rotor cup 302 may be configured to have the fan 304 mounted on a surface of the rotor cup 302. The fan 304 may be mounted such that a rotor boss 310 extending from the rotor cup 302 and the fan 304 are centrally aligned.

The at least two magnet 306 may further be mounted on the fan 304, and further positioned circumferentially on walls 312 of the rotor cup 302. The at least two magnets 306 may be sandwiched between the walls 312 on a first side and the magnet case 308 on a second side. The magnet case 308 may be configured to hold the at least two magnets against the wall 312. The magnet case 308 in accordance with another exemplary embodiment may provide shielding to the at least two magnets 306 from the heat generated in the stator and stator winding and thus reducing the problem of demagnetization.

The magnet case 308 may further be mounted on the fan 304. The magnet case 308 and at least two magnet separators 314 provided on the fan 304 enable correct and easy alignment of the at least two magnets 306.

In another exemplary embodiment the fan 304 may be made of plastic to reduce the weight of the assembly. In one non-limiting embodiment, the fan 304 may be made up of any material known to a person skilled in the art. Further the number of magnet separator 314 may depend on the number of magnets mounted on the fan 304.

The foregoing description shall be interpreted as illustrative and not in any limiting sense. A person of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure.

The embodiments, examples and alternatives of the preceding paragraphs or the description and drawings, including any of their various aspects or respective individual feature(s), may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible.