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IIIII II/I I IIIII /Ill II /Ill Ill
200324193
FIELD OF INVENTION
[0001] The present invention relates to a water pump, and more particularly
the present invention relates to an electric water pump for thermal management
system used in vehicles.
BACKGROUND OF THE INVENTION
[0002] In automotive sectors thermal management system performs very
important role in vehicles i.e. in commercial vehicles. To control the temperature
10 of the electric motor, inverter, battery and other systems water pump is used to
reduce the temperature. In this period of time the automotive sector is turning to
electrical vehicles. The electrical water pump is used mostly in electrical vehicles
as thermal management system.
[0003] The conventional electrical water pump consists of volute casing with
15 inlet and outlet, screw for connecting housing & rotor casing, shroud, impeller
connected to rotor, rotor casing, oring, stator with windings and terminals, oring,
housing, controller, cover, screw.
[0004] In the conventional electrical water pump the winding of stator is done
by needle winding, it is very difficult process of winding, it takes more time for
20 a single coil. Therefore productivity is less.
[0005] To overcome aforementioned drawbacks present in the conventional
electric water pump, there is a need of an electric water pump with improved stator.
OBJECTS OF THE INVENTION
[0006] The main object of a present invention is to provide an electric water
25 pump with improved stator.
[0007] The another object of the present invention is to provide an electric
water pump with improved stator that reduce the cycle time taking for coil winding.
2
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[0008] The another object of the present invention is to provide an electric
water pump with improved stator that increases productivity.
[0009] The another object of the present invention is to provide an electric
water pump with improved magnet that is cost efficient.
5 SUMMARY OF THE INVENTION
[00010] The present invention relates to a water pump, and more particularly
the present invention relates to an electric water pump for thermal management
system used in vehicles.
[00011] An electric water pump with improved stator ( 1 00), the pump ( 1 00)
10 includes a housing ( 40), a volute casing (I 0) having atleast one inlet ( 170) and
atleast one outlet (180), the volute casing (I 0) coupled to housing ( 40) by fastening
means, a shaft (140) coupled to housing (40) by manufacturing process, a stator
assembly (50) coupled to housing (40) by fastening means, a rotor assembly (20)
having a shroud ( 120), an impeller (190), a plurality of bushes (220) and a magnet
15 (30), a cover (11 0) coupled to housing ( 40) by fasteners (80), and a controller (70)
operably coupled to bottom of the housing ( 40)/stator assembly (50) by fasteners
for controlling the speed of pump. The stator assembly (50) having a coil (52), a
bobbin (51) capable of receiving the coil (52), a plurality of teeth (53) stamped
together and a lamina assembly (54) capable of receiving the plurality of slot teeth
20 (53).
[00012] In an aspect of present invention the bobbin (51) including a cavity
(51 a), a plurality of grooves (51 b) capable of receiving winding connection with
terminal, an extended ends (51 c) and an middle (51 d) configured for receiving the
coil.
25 [00013] In an aspect of present invention the lamina assembly (54) including a
housing, a plurality of teeth inside housing, a plurality of grooves capable of
receiving the slot teeth (53) not shown.
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[00014] In an aspect of present invention the slot teeth (53) including a circular
top (53a) configured to fit inside circular groove of lamina assembly (54) and an
inverteJ T bottom (53b).
[00015] In an aspect of present invention the lamina assembly (54) including
5 three grooves receives three slot teeth (53).
[00016] In an aspect of present invention the lamina assembly (54) including six
teeth inside housing.
[00017] In an aspect of present invention the end portion of inverted T the slot
teeth (53) having circular shape.
10 [00018] In an aspect of present invention a method for winding the stator
includes steps of, winding the bobbin (51) by the coil (52), inserting the slot teeth
(53) to the cavity (51 a) ofthe bobbin (51), inserting the slot teeth (53) to the groove
of lamina assembly (54) and repeating the steps for next bobbin (51).
[00019] In an aspect of present invention the method for winding the stator
15 increases the productivity and reduces the cycle time.
[00020] In an aspect of present invention the bobbin is made up of but not
limited to plastic or thermoplastic.
BRIEF DESCRIPTION OF THE DRAWINGS
[00021] The accompanying drawings constitute a part ofthe description and are
20 used to provide further understanding of the present invention. Such accompanying
drawings illustrate the embodiments of the present invention which are used to
describe the principles of the present invention together with the description.
[00022] Fig. 1 shows a cross sectional view of a conventional water pump
disclosed in the prior art;
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[00023] Fig. 2 shows a cross sectional view of an electric water pump with
improved stator in accordance with the preferred embodiment of a present
invention.
[00024] Fig. 3 shows an exploded view of an electric water pump with improved
5 stator in accordance with the preferred embodiment of a present invention.
[00025] Fig. 4 shows exploded view of stator assembly in accordance with the
preferred embodiment of a present invention.
[00026] Fig. Sa and Fib 5b shows bottom and top views of stator assembly in
accordance with the preferred embodiment of a present invention.
10 [00027] Fig. 6 shows views of bobbin in accordance with the preferred
embodiment of a present invention.
[00028] Fig. 7 shows views of slot teeth m accordance with the preferred
embodiment of a present invention.
[00029] Fig 8 shows comparison of an electric water pump with improved stator
15 with conventional/prior art pump with cycle time parameter.
DETAILED DESCRIPTION OF THE INVENTION
[00030] As used in the description herein and throughout the claims that follow,
the meaning of "a," "an," and "the" includes plural reference unless the context
clearly dictates otherwise. Also, as used in the description herein, the meaning of
20 "in" includes "in" and "on" unless the context clearly dictates otherwise.
[00031] If the specification states a component or feature "may", "can", "could",
or "might" be included or have a characteristic, that particular component or feature
is not required to be included or have the characteristic.
[00032] Exemplary embodiments will now be described more fully hereinafter
25 with reference to the accompanying drawings, in which exemplary embodiments
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are shown. This disclosure may however, be embodied in many different forms and
should not be construed as limited to the embodiments set forth herein.
[00033] The present invention relates to a water pump, and more particularly
the present invention relates to an electric water pump for thermal management
5 system used in vehicles.
[00034] Referring Fig 2, Fig 3, Fig 4, Fig 5, Fig 6 and Fig 7, an electric water
pump with integrated rotor (1 00), the pump (1 00) includes a housing ( 40), the
housing (40) made up of but not limited to metal or non metal or plastic or
thermoplastic, a volute casing (1 0) having atleast one inlet (170) and atleast one
10 outlet (180), the volute casing (10) made up of but not limited to metal or non metal
or plastic or thermoplastic well known in the art, the volute casing (1 0) coupled to
housing (40) by fastening means like but not limited to spin welding or press fitting
or alike, a shaft (140) coupled to housing ( 40) by manufacturing process process
like but not limited to injection molding or insert molding or press fitting or snap
15 fitting or casting or alike, the shaft (140) made up of but not limited to stainless
steel, a stator assembly (50) coupled to housing ( 40) by fastening means, a rotor
assembly (20), a cover (11 0) coupled to housing ( 40) by fasteners (80) and a
controller (70) operably coupled to bottom of the housing ( 40)/stator assembly (50)
by fasteners for controlling the speed of pump. The stator assembly (50) includes a
20 coil (52), a bobbin (51) capable of receiving the coil (52), a plurality ofteeth (53)
stamped together and a lamina assembly (54) capable of receiving the plurality of
slot teeth (53). The lamina assembly (54) made up of but not limited to metal or
stainless steel or alike. The coil (52) made up of but not limited to metal or copper
or alike. The bobbin (51) made up of but not limited to non metal or plastic or
25 thermoplastic or alike. The terminals made of but not limited to metal or brass or
alike. The slot teeth made up of but not limited to metal or sheet metal or electrical
steel or alike.
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[00035] In an aspect of present invention the bobbin (51) including a cavity
(51 a), a plurality of grooves (51 b) capable of receiving winding connection with
6
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terminal, an extended ends (51c) and an middle (Sid) configured for receiving the
l:Oi J.
[00036] In an aspect of present invention the lamina assembly (54) including a
housing, a plurality of teeth inside housing, a plurality of grooves capable of
5 receiving the slot teeth (53) not shown.
[00037] In an aspect of present invention the slot teeth (53) including a circular
top (53a) configured to fit inside circular groove of lamina assembly (54) and an
inverted T bottom (53b).
[00038] In an aspect of present invention the lamina assembly (54) including
10 three grooves receives three slot teeth (53).
15
[00039] In an aspect of present invention the lamina assembly (54) including six
teeth inside housing.
[00040] In an aspect of present invention the end portion of inverted T the slot
teeth (53) having circular shape.
[00041] In an aspect of present invention a method for winding the stator
includes steps of, winding the bobbin (51) by the coil (52), inserting the slot teeth
(53) to the cavity (51 a) of the bobbin (51), inserting the slot teeth (53) to the groove
oflamina assembly (54) and repeating the steps for next bobbin (51).
[00042] In an aspect of present invention the method for winding the stator
20 increases the productivity and reduces the cycle time.
[00043] In an aspect of present invention the bobbin is made up of but not
limited to plastic or thermoplastic.
[00044] The bobbin including the end flanges to carry the winding properly. The
winding is done on the bobbin by bobbin winding technique. The terminals are
25 connected to the stator. The controller mounting pad is placed on the stator, the
controller is connected to the controller mounting pad with the screw, the connector
7
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terminals are connected to controller, the rubber seal is placed over the terminals,
and cover is connected to the housing.
[00045] The non limiting operational characteristics of an integrated electric
water pump ( 1 00) is explained here, when the temperature of application (e.g. but
5 not limited to thermal management system of vehicle) is high than limited
temperature, the temperature sensor gives the signal to the controller. Then Pulsewidth
modulation (PWM) (well known in art) of the controller (70) gives the output
signal according to the temperature of application. As PWM signal is given to the
motor, the stator produces rotating magnetic field, such that flux links with the rotor
10 (20) field, then rotor (20) start to rotate at specified speed. Therefore water enters
into the pump by inlet (170), it flows from the impeller (190) and enters in the rotor
housing (40), exits from the outlet (180).
15
[00046] Due to present design of stator assembly winding is easy, cycle time
less for one coil winding, high productivity, shorter flux path, and cost benefit.
[00047] Here bobbin winding is used instead of needle winding it reduces the
time taking for one coil winding, it increases the productivity, also effects on cost.
By using this type of configuration of winding the flux path is shorter.
[00048] In the above detailed description, reference is made to the
accompanying drawings that form a part thereof, however, such description should
20 not be considered as any limitation of scope of the present invention. The structure
thus conceived in the present description is susceptible of numerous modifications
and variations, all the details may furthermore be replaced with elements having
technical equivalence.
25 [00049] ADVANTAGES
1. Winding the coil on bobbin is easy.
2. Cycle time reduced/less for one coil winding.
3. High productivity~
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4. Shorter flux path, cost efficient.
[00050] List of reference numerals:
5 I. An integrated electric water pump ( 1 00)
2. A volute casing (I 0)
3. A rotor assembly (20)
4. An magnet (30)
5. A housing (40)
10 6. A stator assembly (50)
7. A bobbin (51), A cavity (51 a), A plurality of grooves (51 b), An extended
ends (51 c) and An middle receiving coil (51 d)
8. A coil (52)
9. A slot teeth (53), A circular top (53a) and An inverted T bottom (53b)
15 10. A lamina assembly (54)
II. A controller mounting pad (60)
12. A controller (70)
13. A screw fastener (80)
14. A rubber seal (90)
20 15. A cover (II 0)
16. A shroud (120)
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17. A washer thrust (130)
18. A shaft (140)
19. A stator terminals (150)
20. A connector main terminals (160)
5 21. An inlet (170)
10
15
20
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22. An outlet (180)
23. An impeller (190)
24. A connector (21 0)
25. A bush (220)
10
5
10
15
20
25

. CLAIMS
We Claim,
1. An electric water pump with improved magnet (I 00), the pump (I 00)
compnses:
a housing (40);
a volute casing (10) having atleast one inlet (170) and atleast one
outlet (180), the volute casing ( 1 0) coupled to housing ( 40) by
fastening means;
a shaft (140) coupled to housing (40) by manufacturing process;
a stator assembly (50) coupled to housing (40) hy fastening means;
a rotor assembly (20) having a shroud (120), an impeller (190), a
plurality ofbushes (220) and a magnet (30);
a cover (11 0) coupled to housing ( 40) by fasteners (80); and
a controller (70) operably coupled to bottom of the housing
(40)/stator assembly (50) by fasteners for controlling the speed of
pump;
wherein the magnet (30) having a plurality of inner flat surfaces
(30c); a plurality of outer convex surfaces (30a); and a plurality of
outer concave surfaces (30b).
2. The electric water pump with improved magnet (100) as claimed in
claim I, wherein the ratio of the distance of al to the distance of bl is
0.521-1.563.
3. The electric water pump with improved magnet (I 00) as claimed in
claim 1, wherein the ratio of the thickness of a2 to the thickness of b2
is 0.4 72-1.422.
4. The electric water pump with improved magnet (1 00) as claimed in
claim 1, wherein the number of convex surfaces (30a), the number of
concave surfaces (30b) and inner flat surfaces (30c) are equal.
10
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5. The electric water pump with improved magnet (I 00) as claimed in
claim I, wherein the inner surface (JOe) of magnet may forms a
reclaugle UI a syuate UI a IIexaguu ut a uclagutt ut a uecagurr ur alilu:.
6. The electric water pump with improved magnet (I 00) as claimed in
claim 1, wherein a detent torque reduced to 90%.
7. The electric water pump with improved magnet (1 00) as claimed in
claim 1, wherein a weight of magnet reduced to 87.2%.
8. The electric water pump with improved magnet (1 00) as claimed in
claim I, wherein there is very less or no effect on an air gap flux density,
a rated torque and a rated current.
9. The electric water pump with improved magnet (1 00) as claimed in
claim I, wherein the number of: outer convex surfaces (30a) or outer
concave surfaces (30b) or inner flat surfaces (30c) are directly
proportional to the number of poles of rotor.
10. The electric water pump with improved magnet (I 00) as claimed in
claim I, wherein the magnet may be bonded magnet.