Claims:We Claim:
1. The water-cooled submersible motor assembly comprising double bearing assemblies, wherein said submersible motor assembly comprises the rotor-shaft (1), upper housing (5), lower housing (12), two bearings (6) and (13), motor base (15), motor base cover (21);
wherein said water-cooled submersible motor assembly is characterized in said double bearing assemblies support the rotor fitted shaft and effectively nullify the thrust generated while pumping water.
2. The water-cooled submersible motor assembly comprising double bearing assemblies, as claimed in claim 1, wherein towards holding the bearing assemblies the upper housing (5) is positioned near the upper end of the rotor shaft (1) within the main body (10) and the lower housing (12) is positioned near the lower end of said rotor shaft (1) therein.
3. The water-cooled submersible motor assembly comprising double bearing assemblies, as claimed in claim 1, wherein in one preferred embodiment of said submersible motor assembly the upper housing (5) is assembled above upper end ring (9) and wherein the upper thrust bearing (6), upper thrust bearing plate (7) and bronze bush (8) are assembled in outwardly provisioned cavity of the said upper housing (5).
4. The water-cooled submersible motor assembly comprising double bearing assemblies, as claimed in claim 1, wherein in one preferred embodiment of said submersible motor assembly the major components in lower section therein are assembled within and around the downward facing cavity of the lower housing (12) and the upward facing cavity of the motor base (15); wherein the lower housing (12) is placed within the main body (10) after the lower end ring (11) and within said lower housing (12), the bronze bearing is positioned, followed by the lower thrust bearing (13) and the lower thrust bearing plate (14).
5. The water-cooled submersible motor assembly comprising double bearing assemblies, as claimed in claim 1, wherein in one preferred embodiment of said submersible motor assembly, the said motor base (15) is so positioned within the main body (10) that the pivot (19) holds the lower end of the rotor-shaft, firmly sealed therein using the pivot nut (20).
6. The water-cooled submersible motor assembly comprising double bearing assemblies, as claimed in claim 1, wherein in one preferred embodiment of said submersible motor assembly, near the lower end of the said submersible motor assembly the motor base cover (21) is positioned adjoining the motor base (15) and at its outer opening the P.C.D. cup (22) is centrally positioned, followed by mounting of the tension spring (23) within said P.C.D. cup and securing the said assembly therein through the P.C.D. circle (24) and L.N. key bolt(s) (25).
7. The water-cooled submersible motor assembly comprising double bearing assemblies, as claimed in claim 1, wherein the structure and construction of one preferred embodiment of said submersible motor assembly is characterized in at least one of the following functional features associated with itself:
• provides smooth starting and long life;
• low-friction and high wear resistance;
• Proven and reliable design for critical condition;
• High motor efficiency;
• Extra top bearing ensures shaft alignment and stabilization for long life;
• Motor and pump can be operated continuously without damage for long time;
• Low power consumption;
• Pump set running continuously without noise and vibration;
• Design particularly customized for low voltage, ranging between 200v to 450v, in three phase;
• Motor running continuously without heating;
• All parts are made out of high-grade material;
• Allows wire to operate under water for long period;
• Easy rewinding and reparable; and
• In this design there is less Eddy Courant Losses, Friction Losses, Hysteresis and Core Losses.
, Description:Field of the invention:
The present invention generally relates to a water-cooled submersible motor assembly comprising double bearing assemblies; wherein said double bearing assemblies support the rotor fitted shaft and effectively nullify the thrust generated while pumping water. Towards holding these bearing assemblies, the present invention provides two bearing housings; wherein the upper housing around the rotor shaft comprises upper thrust bearing assembly and the lower housing comprises lower thrust bearing assembly.

Background of the invention:
Submersible pumps, particularly comprising of an electric motor and a pump integrated in a multi stage, have got wide applications throughout the world in diverse pumping activities, including pumping of underground water. Towards pumping underground water for domestic purposes and preferably from a depth typically ranging between 50 to 2000 feet, verity of water-cooled submersible pumps is in application; wherein such pumps generally comprise of a metallic cylindrical housing comprising of the assembly of a centrifugal pump, a motor-shaft assembly and a motor protector. A submersible motor is completely enclosed and non-ventilated. It does not have an external shaft-mounted fan to cool and dissipate the heat from the frame.
While in function of pumping liquid, the submersible pump involves substantial centrifugal action of pump and the rotating motor therein at very high RPM and also the motion of the pumped liquid, consequently leading to enough abrasion, heat generation, upward thrust and noise. Such mechanical consequences of abrasion, heat generation, upward thrust and noise are maximum experienced by the submersible pump assembly at the time of start or stop of the motor therein, no-effective supply of electric power, high impurity present with the liquid (water herein) being pumped, depth of the water level, insufficient presence of liquid being pumped etc.
Conventional submersible pumps for domestic & agriculture purposes are provisioned with one thrust bearing, particularly at the lower end of the cylindrical body of said pumps. A cut-away schematic view of the conventional submersible pump is shown in Figure-1, which shows the conventional assembly of the thrust bearing.
Conventional such submersible pumps, available in the market, are generally associated with at least one of the following demerits:
• Operational load bear by one single bearing, hence the life of motor reduces to one season and required replacement of parts, thus the life is less;
• High voltage is required while starting the motor;
• More friction and low wear resistance;
• In case of current fluctuation or improper power supply, this motor could not work;
• Output of the motor is less hence efficiency also less;
• Overall lode on single bearing the shaft dose not rotate properly;
• Pump set cannot run for longer hours due to above mention points, hence burning chances are more;
• Noise and vibration are too high at the time of rotation;
• Pump set working in 415v to 300v only;
• Motor temperature is high due to more power consumption;
• Rewinding and maintenance are not easy; and
• It is observed that there are more eddy current losses, friction losses, hysteresis losses and core losses.
To address the abovementioned drawbacks of conventional submersible pumps, particularly to support smooth functioning of the submersible pump as well as to counter the continuous and high thrust load, the present invention provides a submersible pump comprising of double bearing assemblies; wherein the upper housing around the rotor shaft comprises upper thrust bearing assembly and the lower housing comprises lower thrust bearing assembly.
Object of the present invention:
Prime object of the present invention is to provide a liquid cooled, particularly water-cooled, submersible motor assembly comprising double bearing assemblies; wherein said double bearing assemblies support smooth and safe functioning of the rotor fitted shaft.
Another object of the invention is to provide the upper bearing assembly, provisioned within the upper housing and the lower bearing assembly provisioned within the lower housing.
Another object of the present invention is to provide a liquid-cooled submersible motor assembly comprising double bearing assemblies, which is characterized in one of the following functional features associated with itself:
• provides smooth starting and long life;
• low-friction and high wear resistance;
• Proven and reliable design for critical condition;
• High motor efficiency;
• Extra top bearing ensures shaft alignment and stabilization for long life;
• Motor and pump can be operated continuously without damage for long time;
• Low power consumption;
• Pump set running continuously without noise and vibration;
• Design particularly customized for low voltage, ranging between 200v to 450v, in three phase;
• Motor running continuously without heating;
• All parts are made out of high-grade material;
• Allows wire to operate under water for long period;
• Easy rewinding and reparable; and
• In this design there is less Eddy current losses, Friction losses and Hysteresis and Core losses.
Another object of the present invention is to provide such a water-cooled submersible motor assembly comprising double bearing assemblies which obviates the drawbacks of the conventional submersible pumps.
Short description of the invention:
The present invention generally discloses a water-cooled submersible motor assembly comprising double bearing assemblies; wherein said double bearing assemblies support the rotor fitted shaft and effectively nullify the thrust generated while pumping water. Towards holding these bearing assemblies, the present invention provides bearing housings; wherein the upper housing around the rotor shaft comprises upper thrust bearing assembly and the lower housing comprises lower thrust bearing assembly.
The submersible motor is completely enclosed and non-ventilated. It does not have an external shaft-mounted fan to cool and dissipate the heat from the frame. In wet pit applications, it relies on the liquid in which it is submerged to dissipate the heat from the frame. Its duty cycle is continuous in water with a 15-minute capability in air. In dry pit applications, the motor may run for prolonged periods of time in air and submerged. Because the air does not dissipate heat as well as liquids, the frame usually must be oversized so that more surface area is available to move the heat away from the motor.
Various functional advantages associated with the motor assembly of the submersible pump, as also depicted in the schematic drawings hereinbelow are present, are as under:
1) provides smooth starting and long life;
2) low-friction and high wear resistance;
3) Proven and reliable design for critical condition;
4) High motor efficiency;
5) Extra top bearing ensures shaft alignment and stabilization for long life;
6) Motor and pump can be operated continuously without damage for long time;
7) Low power consumption;
8) Pump set running continuously without noise and vibration;
9) Design particularly customized for low voltage, ranging between 200v to 450v, in three phase;
10) Motor running continuously without heating;
11) All parts are made out of high-grade material;
12) Allows wire to operate under water for long period;
13) Easy rewinding and reparable; and
14) In this design there is less Eddy Courant Losses, Friction Losses, Hysteresis and Core losses.

Detailed Description of the invention:
Major components used for construction of the water-cooled submersible motor assembly with double bearing assemblies include:
Motor tube or main body (10), Stater stack (10A), rotor(1A), copper rod, copper lamination, Poly Venial Chloride (PVC), copper wire, Rotor shaft (1), CI casting parts (2, 5, 15), thrust bearings (6 & 7), bronze bush (8), fasteners etc.
Stator stack is fitted into SS motor tube by hydraulic press machine and winding is completed with inserting PVC winding wire and at same time cable is connected therewith.
Rotor for the said water-cooled submersible motor assembly is processed by inserting copper rods and brazing copper lamination on both ends and then it fits with SS shaft and ready for assembly after turning, grinding and balancing operations.
Cast iron (CI) casting parts consists adopter, upper housing, lower housing and motor base. After machining of the parts, they get ready for assembly.
Assembly or construction done as per following steps:
Motor base holds tension spring and PCD cup and the lower housing. The lower housing comprises lower thrust bearing, coupled with the thrust plat. The said lower housing is fitted with bronze bush, followed by mounting of the motor tube, which is then fitted by fasteners. The rotor fitted shaft is inserted in the tube and rest on thrust bearing.
The upper housing fitted with bronze bush and thrust bearing placed on shaft and assembled with fasteners. At the end adopter is fitted to complete the assembly.
Detailed description of the invention with the help of schematic drawings:
Figure-1: Represents a cut-away schematic view of the conventional submersible pump comprising of one thrust bearing assembly;
Figure-2: Represents complete schematic view of the most preferred embodiment of the water-cooled submersible water-cooled submersible motor assembly comprising double bearing assemblies; wherein said double bearing assemblies support the rotor fitted shaft, as disclosed in the present invention;
Figure-3: Represents partial schematic view of the preferred embodiment of the submersible pump; wherein it depicts the upper section of the pump assembly, particularly the upper housing, as shown in Figure-2 herein;
Figure-4: Represents partial schematic view of the preferred embodiment of the submersible pump; wherein it depicts the middle section of the pump assembly, as shown in Figure-2 herein;
Figure-5: Represents partial schematic view of the preferred embodiment of the submersible pump; wherein it depicts the lower section of the pump assembly, particularly the lower housing, as shown in Figure-2 herein.
Figure-6: Graphical representation relating certain experimental data pertaining to the functional and characteristic features of the most preferred embodiment of said water-cooled submersible motor assembly of the present invention, as depicted in Figures 2 to 5.
The illustrative drawings are labelled with certain numerals towards representing various structural/constructional features of the said top water cooled submersible motor assembly comprising double working bearings, as under:
Regarding prior art, as shown in Figure-1
(a) Spline protector and Sand linger
(b) Built-in Lightning Arrestors
(c) Removable Water-Block Lead Assembly
(d) Biac Starting Switch (2-wire only)
(e) Water lubrication
(f) Stainless steel exterior Construction
(g) Hermetically sealed Stator Windings With Anti-Track Resin System
(h) Self-aligning Kingsbury-Type Thrust Bearing
(i) Pressure Equalizing Diaphragm
Regarding the preferred embodiment of the submersible pump and its structural/constructional features of the present invention, as illustrated in Figures 2 to 5:
1 Rotor- shaft
2 Adapter
3 Upper t-bolt
4 T.B Circlip
5 Upper Housing
6 Upper Thrust Bearing
7 Upper Thrust Bearing Plate
8 Bronze Bush
9 Upper End Ring
10 Motor Body-
11 Lower End Ring
12 Lower Housing
13 Lower Thrust Bearing
14 Lower Thrust Bearing Plate
15 Motor Base
16 Water Drain Plug
17 Lower T-Bolt
18 Cap Nut
19 Pivot
20 Pivot Nut
21 Motor Base Cover
22 P.C. D. Cup
23 Tension Spring
24 P.C.D. Circle
25 L N Key Bolt

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
One preferred embodiment of the water-cooled submersible motor assembly comprising of double bearing assemblies is illustrated in Figure-2. Whole construction of said water-cooled submersible motor assembly is substantially illustrated in Figures 3 to 5.
Main body (10) of the present submersible pump is in the form of a cylindrical tube, preferably made of steel, within which all the components of said water-cooled submersible motor assembly are assembled. The rotor-shaft (1), duly engaged with the rotor (1A), is secured within the main body (10), wherein said rotor (1A) with the stator (10A) is positioned at the middle section of said main body (10).
At the upper section of the said water-cooled submersible motor assembly, the upper housing (5) is assembled above upper end ring (9). Within the outwardly provisioned cavity of said upper housing (5) therein, the upper thrust bearing (6), upper thrust bearing plate (7) and bronze bush (8) are assembled. The upper housing (5) is secured at upper end of the rotor shaft (1) using the T.B. Circlip (4), upper T-bolt (3) and the adopter (2).
At the lower section of the said water-cooled submersible motor assembly, the major components in lower section therein are assembled within and around the outward (i.e. downward) facing cavity of the lower housing (12) and the inward (i.e. upward) facing cavity of the motor base (15). Lower housing (12) is placed within the main body (10) after the lower end ring (11). Within said lower housing (12), the bronze bearing is positioned, followed by the lower thrust bearing (13) and the lower thrust bearing plate (14) therein. Along with the motor base (15), the water drain plug (16) is provisioned, followed by fixedly securing the complete assembly therein using the lower T-bolt (17) and cap nut (18). Said motor base (15) is so positioned within the main body (10) that the pivot (19) holds the lower end of the rotor-shaft, firmly sealed therein using the pivot nut (20). Towards the lower end of the said submersible motor assembly, the motor base cover (21) is positioned adjoining the motor base (15) and at its outer opening the P.C.D. cup (22) is centrally positioned, followed by mounting of the tension spring (23) within said P.C.D. cup and securing the said assembly therein through the P.C.D. circle (24) and L.N. key bolt(s) (25).
Major functional and characteristic features of the most preferred embodiment of the water-cooled submersible motor assembly comprising double bearing assemblies of the present invention, as depicted in Figures 2 to 5, are represented in following illustrative tables: