DESC:FIELD OF INVENTION

The present invention relates to a novel technology which reduces and avoids the impeller (water propelling system) jamming in the regenerative self-priming pump. More particularly, the present invention modified the adapter & casing design by inserting configured in both the adapter & casing to avoid jamming in the constructional operation area with a combination of ferrous materials like Stainless Steel, etc.

BACKGROUND ART

The impeller is placed between the casing & adapter due to the special design of the pump gap between the impeller-casing and the impeller-adapter, which is very small. In regular practice, when the water pump is not used for certain days, for more than five days, galvanic corrosion starts between two dissimilar metals, which leads to a pump jam problem. Sometimes, even if the motor is operated in a jam condition, the motor draws a very high current and burns the winding due to overheating. The rusting of the casing and adapter is shown in Fig 1,

Pump Jam/impeller jamming, as shown in Fig 2, is the most common defect in water pumps. Many times, the consumer has to manually free the pump by removing the volute casing and cleaning the rust portion or forcefully rotate the shaft manually from the fan side to overcome the pump jam. This requires special effort every time in such cases, or they have to call a technician to resolve this issue.

In the prior art, a previous solution was disclosed under patent no. 305872 "prevention of jamming in regenerative pumps due to corrosion". The solution is provided with non-ferrous materials like nylon 66, typical amides, and Engineering plastics, but it does not effectively solve the problem of wear resistance. Insert cover a total wetted area including mechanical seal cavity; it is difficult for manufacturing & fixing for commercialization of the product. To overcome this limitation, we have proposed a wear-resistant & corrosion-resistant stainless-steel insert, which solves wear-out problems effectively, gives reliable performance for longer life & also easy to manufacture.

SUMMARY OF INVENTION

The herein disclosed novel technology reduces and avoids the frequent impeller (water propelling system) jamming in the regenerative self-priming pump due to rusting. This unique technology insert was developed to avoid jamming in constructional operation areas with a combination of ferrous materials like Stainless Steel, etc.

The wear-resistant and corrosion-resistant properties are developed by a unique stainless steel insert provided to the adapter and casing of regenerative self-priming pumps. This insert avoids pump jam due to rusting and achieves constant performance for a longer time by reducing wear and tear of close-contact components.

Regenerative self-priming pumps with high head and low discharge characteristics compared with other centrifugal pumps are used for water handling in domestic, industrial and commercial sectors. To achieve this high head, the design of this pump is in such a way that the impeller, volute casing & adaptor are in very close contact, and the axial gap in these components ranges from 20 microns to 300 microns. The impeller is majorly made up of Brass or Gun metal material, and the volute & adaptor are made of Cast iron material. When these dissimilar metals are in close contact, galvanic corrosion happens and forms a solid bond between the rotating impeller and stationary volute or adaptor, leading to pump jamming. Also, during the operation, foreign particles enter the volute casing along with water and wear out the casing over a period of operation, thereby increasing the axial gap between these two close contact components, leading to deterioration of performance. So, to avoid this issue, we are coming up with the solution of providing the wear-resistant & corrosion-resistant stainless-steel insert fitted in the pump casing and adaptor contact faces.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Fig 1 illustrates a pictorial representation of the Rusting of casing & Adapter as a prior art problem;
Fig 2 illustrates the impeller jamming as a prior art problem;
Fig 3 illustrates a section view of the proposed invention pump assembly in accordance with the present invention;
Fig 4 illustrates a section view of the existing pump assembly in accordance with the present invention;
Fig 5 illustrates an exploded view of the proposed invention pump assembly in accordance with the present invention;
Fig 6 illustrates the geometry of the insert.

DETAILED DESCRIPTION
The impeller is placed between the casing & adapter, and the gap between the impeller-casing & impeller-adapter is very small, as the pump is kept idle for some days, then rusting is initiated & impeller gets jammed. In the present invention, the corrosion resistance inserts fixed on the adapter and casing help to avoid rusting & pump can operate without jamming, even if kept in idle condition. Also, the impeller continuously rotates in between the adapter & casing, so the casing & adapter contact surfaces get worn out over a certain period & reduce performance. In the present invention, Stainless steel inserts have good wear resistance properties, help to avoid wear & give consistent performance for longer periods. The present invention insert can be easily fix on adapter & casing contact faces by anabond and rivet. Easy for mass production and cost-effective solution for improving the reliability of said pump and resolving pump jams and wearing problems.

In water pumps, there are mainly two portions: the motor portion and the pump portion. The function of the motor portion is to give rotational energy to the pump portion, which has to pump water and deliver it from one place to another or at a higher head. The pump portion mainly consists of three components, as shown in Fig.3, and their function is as below.

The impeller is continuously rotating between the adapter and casing. Due to rubbing and friction, the adapter and casing surfaces wear out slowly over time, reducing performance such as head, discharge, and suction capacity over a certain period. In the present invention, the Stainless steel insert has a good wear resistance property, helping to avoid wear and give consistent performance for a longer period.

Impeller [3c]—The Impeller is the rotating member of the pump portion that rotates with the rotational energy of an electrical motor. It imparts its kinetic energy to water and increases the water pressure through regeneration by guiding water flow through multiple vanes of the impeller. MOC-metallic/Non-Metallic, like Brass, Stainless Steel, Plastic (e.g., PPS grade), Nickel/ Chrome plating on Base metal, etc.

Volute/casing [3a]—Volute is also called a pump casing, which houses the pump's suction and discharge ports. From the suction port, water enters the impeller, and then through the delivery port, high-pressure water gets delivered to the externally connected pipe or at the required source. The casing helps to guide water and convert kinetic energy into pressure energy. It is made from materials such as MOC-CI, Plastic, etc.

Adaptor [3b]—The adaptor connects the pump and motor portions together. It also houses the mechanical seal to avoid water leakage through the shaft and is made from materials such as MOC—CI, Plastic, etc.

For the regeneration of pressure in water, the design of this pump is such that the impeller, volute casing & adaptor are in very close contact; the axial gap in these components ranges from 20 microns to 300 microns. The impeller is majorly made up of Brass or Gun metal material, and the volute & adaptor are made of Cast iron material. When these dissimilar metals are in close contact, galvanic corrosion happens and forms a solid bond of rust between the rotating impeller and stationary volute or adaptor, leading to pump jamming. Also, during the operation, foreign particles enter the volute casing along with water and wear out the impeller & casing over a period of operation, thereby increasing the axial gap between these two close contact components, leading to deterioration of performance over a certain period of time.

In order to avoid frequent jamming problems in pumps, the solution is to provide a corrosion-resistant and wear-resistant stainless-steel insert [3d], preferably in the pump casing [3a] and adaptor [3b] on the portion where they are in close contact, as shown in Fig. 3. The differences/modifications can be easily viewable from the section view of existing pumps, as shown in Fig. 4.

Shape & Size [fig. 5] of the insert depends on and varies as per adapter & casing face geometry. Key geometrical parameters are as below.

Parameter Parameter description
R1 Inner radius of insert (same as inner radius of casing & adapter)
R2 Outer radius of insert (same as outer radius of casing & adapter)
R3 Extended Profile radius of insert (same as extended profile radius of casing & adapter)
a, b Outer & Inner width of extended profile respectively (same as outer & inner width of extended profile of casing & adapter respectively)

INVENTIVE STEP
1. As shown in Fig 5, the proposed invention uses corrosion-resistant and wear-resistant stainless steel. In contrast, the previous solution used non-ferrous materials like Nylon 66, typical amides, and any other engineering plastic having wear-resistant properties.
2. The insert design is totally different from the previous solution. In the proposed invention, the insert is provided only to the contact faces (adjacent to the impeller) of the adapter and casing. The insert covered the completely wetted hydraulic portion in the previous solution, including the mechanical seal cavity.
3. The manufacturing and insert fixing methods are totally different. In the proposed invention, the insert is manufactured by sheet metal die operation, fixed on the faces of the adapter/ casing by adhesive Loctite/Anabond, and then riveted for firm fixing. In the previous solution, the insert is made and fixed during the plastic moulding process.

While the present invention has been described with reference to a specific preferred embodiment, it will be apparent that various modifications and changes could be made to this embodiment without departing from the scope of the invention. The above­ mentioned descriptions are provided to clarify the aspects of the invention, and it will be apparent to one skilled in the art that they do not serve to limit the scope of the invention. By way of example, the total assembly is customized. The above-mentioned assembly example is just one of the many configurations that the mentioned components can take on. All modifications and improvements have been incorporated herein for the sake of conciseness and readability but are properly within the scope of the present invention.

,CLAIMS:

1. A pump assembly comprising of;

an impeller [3c] rotating member of the pump portion;
a volute/casing [3a] which houses pump suction and discharge port;
an adaptor [3b] configured to connect the pump and motor portion together, and it also houses the mechanical seal to avoid water leakage through the shaft and
an insert [3d] preferable in pump casing [3a] and adaptor [3b] on the portion where they are in close contact with impeller;
wherein for regeneration of pressure in water, the design of this pump is in such a way that the impeller, volute casing & adaptor are in very close contact, the axial gap in these components ranges from 20 microns to 300 microns
and wherein said insert is made from corrosion-resistant & wear-resistant stainless-steel material.

2. The pump assembly, as claimed in claim 1, wherein said impeller [3c] is configured to impart kinetic energy to water and increase the water pressure through regeneration by guiding water flows through multiple vanes of the impeller.

3. The pump assembly, as claimed in claim 1, wherein said impeller [3c] is made from MOC-metallic/Non-Metallic materials like Brass, Stainless Steel, Plastic (e.g., PPS grade), Nickel/ Chrome plating on Base metal, etc.

4. The pump assembly, as claimed in claim 1, wherein said volute/casing [3a] is configured to guide water & convert kinetic energy into pressure energy.

5. The pump assembly, as claimed in claim 1, wherein said volute/casing [3a] is made from MOC-CI, Plastic, etc.

6. The pump assembly, as claimed in claim 1, wherein said adaptor [3b] connects the pump and motor portion together and also houses the mechanical seal to avoid water leakage through the shaft.

7. The pump assembly, as claimed in claim 1, wherein said adaptor [3b] is made from MOC—CI, Plastic, etc.

8. The pump assembly, as claimed in claim 1, wherein said insert [3d] is provided with only the contact faces (adjacent to the impeller) of the adapter and casing.

9. The pump assembly, as claimed in claim 1, wherein said insert [3d] is manufactured by sheet metal dies operation, fixed on faces of adapter/ casing by adhesive Loctite/and bond and then riveted for firm fixing.

10. The pump assembly, as claimed in claim 1, wherein the inner radius [R1] of said insert is the same as the inner radius of the casing & adapter;
wherein the outer radius [R2] of said insert is the same as the outer radius of the casing & adapter and
wherein the extended Profile radius [R3] of said insert is the same as the extended profile radius of the casing & adapter.