DESC:FIELD OF THE INVENTION
The present invention relates to a self-cooled electric water pump. More particularly, the present invention relates to a self-cooled electric water pump which offers a cooling effect to the critical components of electric water pump such as printed circuit board (PCB), motor and rotor by circulating a coolant via primary, secondary and tertiary flow paths.

BACKGROUND OF THE INVENTION
An electric water pump is a device that uses an electric motor to circulate water or other fluids. These pumps are used in a variety of applications, including residential, commercial, and industrial settings. In commercial and industrial settings, electric water pumps are used for a variety of purposes, such as cooling systems, process water circulation, and wastewater treatment.
An electric water pump in a vehicle is used to circulate coolant through the engine and radiator to regulate the temperature of the engine. The electric water pump replaces the traditional mechanical water pump that is driven by a belt connected to the engine.
Electric water pumps in vehicles are becoming increasingly common, especially in hybrid and electric vehicles, where they are used to circulate coolant through the battery pack to maintain optimal temperature and prolong battery life. They are also used in high-performance vehicles to provide greater control over the cooling system and reduce the load on the engine.
Electric water pumps offer several advantages over mechanical water pumps, including improved fuel efficiency, reduced emissions, and increased reliability. They are also quieter and require less maintenance than traditional mechanical water pumps.
Electric water pumps in vehicles are typically powered by the vehicle's electrical system and are controlled by the engine control module (ECM) or a dedicated pump controller. The ECM or controller monitors the engine temperature and controls the speed of the pump to maintain the desired temperature range.
Cooling of the electric water pump in a hybrid vehicle is critical to ensure proper operation and longevity of the pump. Since the electric water pump is powered by electricity, it generates heat during operation, which must be dissipated to prevent damage to the pump and other components.
In most hybrid vehicles the electric traction motor is an alternate for engine and in most electric vehicles the engines are replaced by electric traction motor, in these vehicles many components like, electric traction motor, inverters, power electronics and needs to be cooled for proper functioning of vehicles.
Electric water pump is used in these vehicles to pump and circulate the coolant through the surrounding of these above stated components of electric and hybrid vehicles to cool these components. Hence, electric water pump plays an important role in hybrid and electric vehicles.
Therefore, proper cooling of the electric water pump itself is essential for reliable and efficient operation of the electric and hybrid vehicle. If the electric water pump becomes overheated, it can fail and cause damage to above stated components of electric vehicle. Therefore, it is important to cool or control the temperature of electric water pump motor and PCB.
As of now the electric water pump (pump’s motor and PCB) is external air cooled, in which fins are provided on casted housing, which has some disadvantages and limitations.
CN1844680A discloses a water-cooling energy-saving water pump, which comprises a water pump and a motor. Wherein, the motor axle is hollow, whose end is connected to the blade wheel is a through hole, another end is sealed; the hollow chamber of motor axle contains a hollow tube whose one end is connected to the motor axle that has through hole to form sealing, and another end has a slit between the motor axle that with sealing end to flow water; the outer diameter d of hollow tube is small than the inner diameter D of motor axle; the motor axle has holes at the part of high-pressure water chamber, to connect the hollow chamber and the high-pressure water chamber. However, this invention does not provide an efficient solution to cool down the components of the water pump.
Therefore, there is a requirement of a self-cooled electric water pump to improve the cooling of critical components such as motor and PCB components.

OBJECT OF THE INVENTION
The main object of the present invention is to provide a self-cooled electric water pump to improve the cooling of critical components such as motor, rotor and PCB components.
Another object of the present invention is to provide to a self-cooled electric water pump for increasing the motor efficiency.
Yet another object of the present invention is to provide a self-cooled electric water pump that works without cooling fins, which makes it cost-effective.
Still another object of the present invention is to provide a self-cooled electric water pump that circulates the coolant through secondary and tertiary paths which cools the motor, rotor and PCB components of electric water pump.

SUMMARY OF THE INVENTION
The present invention is directed towards a self-cooled electric water pump that controls the temperature of critical components by permitting the coolant to flow through secondary and tertiary paths, thereby resulting into an increase in overall pump efficiency.
In an embodiment, the present invention provides a self-cooled electric water pump comprising a volute casing; a housing; a coolant inlet; a coolant outlet; an electric connector; an impeller; a separator; a cover; a bush; a stator motor; a rotor magnet; and printed circuit board. The volute casing is attached to said housing. The housing accommodates said impeller, said bush, said stator motor, said rotor magnet, and said printed circuit board is pasted below said separator by using a thermal paste and enclosed through said cover. The housing has a plurality of flow paths provided therein with a flow channel to facilitate the flow of coolant via said coolant inlet. The coolant passes through said connection path cooling the electronic components of said electric water pump and then exit through said coolant outlet of said volute casing under the coolant pressure generated by said impeller of said electric water pump.
The above objects and advantages of the present invention will become apparent from the hereinafter set forth brief description of the drawings, detailed description of the invention, and claims appended herewith.

BRIEF DESCRIPTION OF THE DRAWINGS
An understanding of the self-cooled electric water pump of the present invention may be obtained by reference to the following drawing:
Figure 1 is a perspective view of the self-cooled electric water pump, according to an embodiment of the present invention.
Figure 2 is a cross-sectional view of the self-cooled electric water pump, according to an embodiment of the present invention.
Figure 3 is a cross-sectional view of the self-cooled electric water pump with primary flow path, according to an embodiment of the present invention.
Figure 4 is a cross-sectional view of the self-cooled electric water pump with secondary flow path, according to an embodiment of the present invention.
Figures 5(a) to 5(d) are isometric view of the self-cooled electric water pump with secondary flow path and tertiary flow path, according to an embodiment of the present invention.
Figure 6 is a cross- sectional view of the self-cooled electric water pump with tertiary flow path, according to an embodiment of the present invention.
Figure 7(a) and Figure 7(b) are cross-sectional views of the self-cooled electric water pump with all three flow paths (primary, secondary and tertiary flow path), according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described hereinafter with reference to the accompanying drawings in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art.
Many aspects of the invention can be better understood with references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts through the several views in the drawings. Before explaining at least one embodiment of the invention, it is to be understood that the embodiments of the invention are not limited in their application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The embodiments of the invention are capable of being practiced and carried out in various ways. In addition, the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
The present invention is directed towards a self-cooled electric water pump that controls the temperature of critical components by permitting the coolant to flow through secondary and tertiary paths, thereby resulting into an increase in overall pump efficiency.
In an embodiment, the present invention provides a self-cooled electric water pump. The pump comprises a volute casing; a housing; a coolant inlet; a coolant outlet; an electric connector; an impeller; a separator; a cover; a bush; a stator motor; a rotor magnet; and printed circuit board. The volute casing is attached to said housing. The housing accommodates said impeller, said bush, said stator motor, said rotor magnet, and said printed circuit board is pasted below said separator by using a thermal paste and enclosed through said cover. The housing has a plurality of flow paths provided therein with a flow channel to facilitate the flow of coolant via said coolant inlet. The coolant passes through said connection path cooling the electronic components of said electric water pump and then exit through said coolant outlet of said volute casing under the coolant pressure generated by said impeller of said electric water pump.
Referring to Figure 1, a perspective view of the self-water-cooled electric water pump is depicted. The self-water-cooled electric water pump (1) comprises of a volute casing (2), a housing (3), a coolant inlet (4), a coolant outlet (5) and an electric connector (6) .The coolant inlet (4) directs a coolant into said self-water-cooled electric water pump (1) under the coolant pressure generated by said impeller (7) to pass through a plurality of flow paths (15, 16, 17) and passes through a connection path (18, 19) provided in the housing (3) to facilitate the flow of coolant around the different electronic components of said water pump (1) absorbing the heat produced by the different electronic components and said coolant outlet (3) guides the coolant to exit through said water pump (1) allowing the water pump (1) to control the pump temperature. The electric connector (6) is connected to a power supply provided to energize said electric water pump (1).
Referring to Figure 2, a cross-sectional view of the self-cooled electric water pump is depicted. The self-cooled electric water pump (1) further comprises a volute casing (2) attached to a housing (3). The housing (3) accommodates an impeller (7), a bush (10), a stator motor (11), a rotor magnet (12), and a printed circuit board (14) that is pasted below said separator (8) by using a thermal paste (13) and enclosed through the cover (9). The separator (8) is preferably made up of plastic or a like material.
Referring to Figure 3, a cross-sectional view of the self-cooled electric water pump with primary flow path is depicted. The housing (3) has a primary flow path (15) provided therein to pass the coolant via a coolant inlet (2) through an impeller (7) and exits through the coolant outlet (3).
Referring to Figure 4, a cross-sectional view of the self-cooled electric water pump with secondary flow path is depicted. The housing (3) has a secondary flow path (16) with a pocket arrangement (20) provided in the perimeter region of said housing (3).The secondary flow path (16) has a pocket arrangement (20) that provides a flow channel to facilitates the flow of coolant around a stator motor (11) under the coolant pressure generated by an impeller (7) of an electric water pump (1). The coolant enters through said coolant inlet (4) and passes through said pocket arrangement (20) provided around a stator motor (11). The coolant circulates around said stator motor (11) under the coolant pressure and passing through a connection path (18), absorbing the heat from the said stator motor (11) and said printed circuit board (14) of said electric water pump (1) and then exits through a coolant outlet (5). The pocket arrangement (20) provided around the pole of said stator motor (11) and are arranged according to the number of poles in said stator motor (11).
Referring to Figures 5(a) to 5(d), isometric views of the self-cooled electric water pump with secondary and tertiary flow path is depicted. In the secondary flow path (16) the coolant enters via said coolant inlet (4) under the coolant pressure generated by said impeller (7) of said electric water pump (1) and enters in a pocket arrangement (20) provided around the stator motor (11). The coolant circulates around the stator motor (11) and passes through a connection path (18), absorbing the heat from the said stator motor (11) and said printed circuit board (14) of said electric water pump (1) and then exits through said coolant outlet (5) of said volute casing (2). In tertiary flow path (17) the coolant enters via said coolant inlet (4) under the coolant pressure generated by said impeller (7) of said electric water pump (1) and enters in a pocket arrangement (21) provided around the rotor magnet (12). The coolant circulates around the rotor magnet (12) and passes through a connection path (19), absorbing the heat from the said rotor magnet (12) and said printed circuit board (14) of said electric water pump (1) and then exits through said coolant outlet (5) of said volute casing (2).
Referring to Figure 6, a cross-sectional view of the self-cooled electric water pump with tertiary flow path is depicted. The housing (3) has a tertiary flow path (17) with a pocket arrangement (21) provided the around the rotor magnet (12). The tertiary flow path (17) has a pocket arrangement (21) that provides a flow channel to facilitate the flow of coolant around a rotor magnet (12) under the coolant pressure generated by an impeller (7) of an electric water pump (1). The coolant enters through said coolant inlet (4) and passes through said pocket arrangement (21) provided around a rotor magnet (12). The coolant circulates around said rotor magnet (12) passing through a connection path (19), absorbing the heat from the said rotor magnet (12) and said printed circuit board (14) of said electric water pump (1) and then exits through a coolant outlet (5).
Figure 7(a) and Figure 7(b), another sectional views of the self-cooled electric water pump with all three flow paths (primary flow path (15), secondary flow path (16) and tertiary flow path (17) is depicted. In the primary flow path (15) the coolant enters from a coolant inlet (4) get pressurized as the impeller (7) rotates and then exits through the outlet (3). In the secondary flow path (16) the coolant enters via said coolant inlet (4) under the coolant pressure generated by said impeller (7) of said electric water pump (1) and enters in a pocket arrangement (20) provided around the stator motor (11). The coolant circulates around the stator motor (11) and passes through a connection path (18), absorbing the heat from the said stator motor (11) and said printed circuit board (14) of said electric water pump (1) and then exits through said coolant outlet (5) of said volute casing (2). In tertiary flow path (17) the coolant enters via said coolant inlet (4) under the coolant pressure generated by said impeller (7) of said electric water pump (1) and enters in a pocket arrangement (21) provided around the rotor magnet (12). The coolant circulates around the rotor magnet (12) and passes through a connection path (19), absorbing the heat from the said rotor magnet (12) and said printed circuit board (14) of said electric water pump (1) and then exits through said coolant outlet (5) of said volute casing (2).
The cooling by the coolant which is in liquid state, is effective than air-cooling since the air cooling cannot work effectively when vehicle is started but not moving (no air flow through fins) but the water cooling starts along with pump (1) start and effectively cool the components.
The coolant used herein refers to water or coolant (50% water and 50% coolant) or any suitable liquid based on the target application.
Therefore, the present invention provides a self-cooled electric water pump that is efficient as the cooling of the components starts as soon as pump starts. In case of the existing air-cooled water pumps, the cooling of pump inside components starts only when the vehicle starts moving since it needs flowing air to pass though the fins to cool water pump inside components, the liquid based cooling is more efficient compared to air cooling, as it instantly cools the inside components. Further the present invention is cost effective as no extra and complex arrangement have to be done in the pump, and through the self-cooling feature, efficiency of the pump is also increased.
Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
The foregoing description of embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principals of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.
,CLAIMS:CLAIMS

We claim:
1. A self-cooled electric water pump (1), comprising:
a volute casing (2); a housing (3); a coolant inlet (4); a coolant outlet (5); an electric connector (6); an impeller (7); a separator (8); a cover (9); a bush (10); a stator motor (11); a rotor magnet (12); and a printed circuit board (14);
wherein;
said volute casing (2) is attached to said housing (3);
said housing (3) accommodates said impeller (7), said bush (10), said stator motor (11), said rotor magnet (12), and said printed circuit board (14) is pasted below said separator (8) by using a thermal paste (13) and enclosed through said cover (9); and
said housing (3) has a plurality of flow paths (15, 16, 17) provided therein with a flow channel to facilitate the flow of coolant via said coolant inlet (4) passes through a connection paths (18, 19) cooling the electronic components of said electric water pump (1) and then exit through said coolant outlet (5) of said volute casing (2) under the coolant pressure generated by said impeller (7) of said electric water pump (1).
2. The self-cooled electric water pump (1) as claimed in claim 1 wherein, said housing (3) has a primary flow path (15) provided therein to pass the coolant via said coolant inlet (4) through said impeller (7) and exit through said coolant outlet (5) of said volute casing (2).
3. The self-cooled electric water pump (1) as claimed in claim 1 wherein, said housing (3) has a secondary flow path (16) provided therein to pass coolant through said connection path (18) cooling said stator motor (11) and said printed circuit board (14) of said electric water pump (1) and then exits through said coolant outlet (5) of said volute casing (2).
4. The self-cooled electric water pump (1) as claimed in claim 3 wherein, said secondary flow path (16) has a plurality of pocket arrangement (20) provided therein around said stator motor (11) being provided to take out the heat produced by said stator motor (11).
5. The self-cooled electric water pump (1) as claimed in claim 4 wherein, said plurality of pocket arrangement (20) provided around the pole of stator motor are arranged according to the number of poles in said stator motor (11).
6. The self-cooled electric water pump (1) as claimed in claim 1 wherein, said housing (3) has a tertiary flow path (17) provided therein to pass coolant through said connection path (19) cooling said rotor magnet (12) and said printed circuit board (14) of said electric water pump (1) and then exits through said coolant outlet (5) of said volute casing (2).
7. The self-cooled electric water pump as claimed in claim 1 wherein, said tertiary flow path (17) with a plurality of pocket arrangement (21) provided therein around said rotor magnet (12) being provided to take out the heat produced by said rotor magnet (12).