FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13) PUMP
KIRLOSKAR BROTHERS LTD.
an Indian Company of Udyog Bhavan, Tilak Road, Pune 411 002,
Maharashtra, India.
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates to pumps.
Particularly, the present invention relates to pumps having improved sealing arrangements.
BACKGROUND OF THE INVENTION
A pump is a device used to move fluids, such as liquids, gases, or slurries. Generally, the pump includes an impeller which is connected to a motor by means of a shaft housed in a casing. The shaft that drives the impeller penetrates the pressure boundary of the pump casing. Wear and tear takes place at the point where the impeller and the pump casing come in contact. This wear and tear is due to the erosion caused by fluid leaking through this tight clearance and friction. Due to continuous wear, the clearance becomes larger and the rate of leakage increases. Eventually, the leakage becomes unacceptably large and maintenance is required to be carried out. Therefore, it is important that the pump is designed to control the amount of fluid that leaks along the shaft at the point at which the shaft penetrates the pump casing.
There are many different apparatus and methods of sealing the leakage past the shaft at point of penetration of the shaft in the pump casing. Factors considered when choosing a method of sealing include the pressure and temperature of the fluid that is being pumped, the size of the

pump, and the chemical and physical characteristics of the fluid to be pumped.
One method of minimizing the leakage is achieved by providing wearing rings. Wearing rings are replaceable rings that are attached to the impeller and/or the pump casing to allow a small running clearance between the impeller and the pump casing without causing wear of the actual impeller or pump casing material. The wearing rings are required to be periodically replaced during the life of the pump.
Another method of minimizing leakage past the shaft is achieved by the use of gland packed arrangement wherein a stuffing box is provided with a set of soft gland packing and a lantern ring. The use of the stuffing box controls the leakage of the fluid to 60 to 80 drops per minute. The lantern ring is provided with a pressurized water connection either through pump casing or from external source thus forming a water cage around it. The use of the stuffing box with the soft gland packing and the lantern ring causes huge wastage of the fluid and creates unpleasant environment near by the pump. Moreover, if the liquid handled by pump is process liquid and harmful to environment, the use of gland packed arrangement can be hazardous.
In order to overcome the drawbacks of the gland packing arrangement, a mechanical seal has been introduced which is fitted in order to prevent the leakage of the stuffing box side. The mechanical seal has a stationary ring and a rotating unit as major two components. The mechanical seal prevents leakage of liquid with the help of an 0-ring at the shaft sleeve, mating face and a stationary ring. The use of the mechanical seal requires precision maintenance. A slight misalignment of the components of the mechanical

seal can damage the seal leading to leakage of the fluid. Also the mechanical seal has limited use in case the fluid to be pumped has the property of crystallization or has solid contents. Flushing is mandatory for mechanical seal and if external liquid is used for flushing, it may lead to the contamination of the process fluid due to mixing with the process fluid. The mixing of the process fluid with the external fluid is not permitted in most cases,
Accordingly, there is a need for a pump that is comparatively more effective in leakage prevention. Further, there is a need for a pump that has comparatively low cost. Also, there is a need for a pump that is simple in construction.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a pump that is comparatively more effective in leakage prevention.
Another object of the present invention is to provide a pump that has comparatively low cost.
Yet another object of the present invention is to provide a pump that is simple in construction.
Still another object of the present invention is to provide a pump that reduces the frequency of periodical maintenance.
An additional object of the present invention is to provide a pump that reduces the cost of maintenance.

One more object of the present invention is to provide a pump that is reliable in operation.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention there is provided a pump. The pump includes an impeller, a pump housing, a drive shaft, a sleeve, a bush, a fluid arrestor and an expeller. The pump housing is adapted to accommodate the impeller therein. The drive shaft is adapted to rotatably mount the impeller thereon, wherein a part of the drive shaft is inside the pump housing and a remaining part of the drive shaft is outside the pump housing. The sleeve is disposed on the drive shaft. The sleeve has a plurality of grooves configured thereon. The bush is disposed on the sleeve, wherein a clearance is provided between the bush and the sleeve. The fluid arrestor is disposed on the sleeve. The expeller is disposed on the sleeve, wherein the expeller, the fluid arrestor, the sleeve and the bush are adapted to provide sealing between the drive shaft and the pump housing.
Typically, a stuffing box chamber has a cavity for collection of fluid therein.
Preferably, the impeller has at least one back vane.
Further, a connecting tube is functionally coupled to the expeller.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention will now be described in relation to the accompanying drawings in which,
Figure 1 illustrates a sectional view of a pump, in accordance with one embodiment of the present invention; and
Figure 2 illustrates an enlarged sectional view of the pump of Figure 1 depicting sealing arrangements thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Preferred embodiments will now be described in detail with reference to the accompanying drawings. The preferred embodiments do not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration.
The present invention provides a pump that is comparatively more effective in leakage prevention. In one embodiment of the present invention, the pump of the present invention may be a centrifugal pump. In another embodiment of the present invention, the pump may be an end suction centrifugal pump. However, the present invention is not limited to any particular pump. Alternatively, the components, elements, or principles of the present invention may be used in any other pumps known in the art for improving sealing characteristics thereof.

Referring to Figures 1 and 2, a pump 10 is described, in accordance with one embodiment of the present invention. The pump 10 includes an impeller 12, a pump housing 14 (shown in Figure 2), a drive shaft 16, a sleeve 18, a bush 20 (shown in Figure 2), a fluid arrestor 22 (shown in Figure 2) and an expeller 28.
In one embodiment of the present invention, the impeller 12 has back vanes 24. The back vanes 24 are adapted to repel back the fluid entering in the space between the impeller 12 and a stuffing box cover 26 to the volute casing of the pump 10. Alternatively, in another embodiment of the present invention, the impeller 12 has at least one back vane, such as back vane 24, for repelling back the fluid entering in the space between the impeller 12 and the stuffing box cover 26 to the volute casing of the pump 10. Accordingly, the present invention is not limited to any number of back vanes used.
The pump housing 14 is adapted to accommodate the impeller 12 therein. The drive shaft 16 is adapted to rotatably mount the impeller 12 thereon, wherein a part of the drive shaft 16 is inside the pump housing 14 and a remaining part of the drive shaft 16 is outside the pump housing 14. The drive shaft 16 is connected to a motor for driving the impeller 12.
The sleeve 18 is disposed on the drive shaft 16. The sleeve has a plurality of grooves (not shown) configured thereon. The bush 20 is disposed on the sleeve 18 and fitted in the stuffing box cover 26. In one embodiment of the present invention, a clearance is provided between the sleeve 18 and the bush 20. The clearance may be a close clearance. A part of the fluid enters through the clearance. The grooves configured on the sleeve 18 are adapted

to facilitate pushing back of the part of the fluid that enters through the clearance to the volute chamber.
The fluid arrestor 22 is disposed on the sleeve 18 on motor side. The fluid arrestor 22 is adapted to prevent air from entering a stuffing box chamber 30 (shown in Figure 2) and thus prevents de-priming of the pump 10. Again in the event of positive suction of the pump, the fluid arrestor 22 prevents the fluid from leaking out of the pump 10 through the drive shaft 16 towards the motor side. The expeller 28 is positioned adjacent the fluid arrestor 22.
The stuffing box chamber 30 has a cavity for collection of fluid therein, the cavity is adapted to collect some of the fluid therein. In one embodiment of the present invention, the fluid collected in the cavity of the stuffing box chamber 30 is transferred to the suction end of the pump 10 with the help of the expeller 28. In one embodiment of the present invention, the pump 10 further includes a connecting tube 32 (shown in Figure 2) functionally connected to the expeller 28. Also, the connecting tube 32 is connected to a suction portion of the pump 10. The expeller 28 is adapted to repel back the fluid escaped from the clearance between the sleeve 18 and the bush 20 towards the suction portion of the pump 10 through the connecting tube 32. Also, the expeller 28 is adapted to repel back the fluid escaped from the clearance between the sleeve 18 and the bush 20 towards the sleeve 18. Accordingly, the expeller 28, the fluid arrestor 22, the sleeve 18 and the bush 20 are adapted to provide sealing between the drive shaft 16 and the pump housing 14.

TEST ANALYSIS
A prior art pump having gland packing arrangement was analyzed in comparison with the pump of the present invention. The Test Analysis was as follows:

Sr.No. Prior Art Pump with Gland Packing arrangement Pump of the present invention
1 This pump has been running in This pump is running in the same
Cast Iron Foundry since last Cast Iron Foundry since last 14 month
two years. Almost 8 hrs per day Almost 8 hrs per day
2 Continuous leakage of water No drop of water was lost in last
of about 70-80 drops per entire 14 months of operation
minutes in its operation.
3 This drops were measured and In fact here this leakage was
roughly it was 0.32 ml per redirected in volute casing and thus
second and thus 1.5lits/hr and 1 2 Its/day loss of water every day we observed in last two years totally save the water.
4 After every three months in Nothing was happened to any
last 2 years we used to component and the pump was
change the gland packing for running without any replacement or
said pump the change of the components.
5 In one more location, at compressor house same prior art pump with mechanical seal arrangement stuffing box was

installed one year back and observe the zero leakage.
6 This mechanical seal needed Here there was no need of external
external clear water for the flushing at stationary and rotating faces which was at the rate of 3 liters/minutes clear water.


7 This pump required perfect No such critical alignment was
stringent maintenance and needed to maintain since last 14
need to check alignments months. Once in three months we
every 1 5 days by using dial check the alignment by using straight
gauge and to be maintain edge. Little misalignment was also
within 50 micron. Needed to affordable. Running with 70-80
replace seal faces once in last one year due to mis-alignment of pump. micron misalignment.
8 Seal faces were damaged and Even such particle entered any time
replaced one more time due to no such damage occurred in last 14
external particle entered between mating faces through external flushing water months.
TECHNICAL ADVANCEMENTS AND ECONOMIC SIGNIFICANCE
The pump of the present invention is comparatively more effective in leakage prevention. More specifically, the pump of the present invention intends to provide zero leakage. Further, the pump has comparatively low cost. Moreover, the pump is simple in construction. Also, the pump reduces the frequency of periodical maintenance. Additionally, the pump of the present invention reduces the cost of maintenance. Furthermore, the pump is reliable in operation.
The numeral values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that values higher or lower than the numerical value assigned to the physical parameters,

dimensions and quantities fall within the scope of the invention and the claims unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim:
1. A pump comprising:
• an impeller;
• a pump housing adapted to accommodate said impeller therein;
• a drive shaft adapted to rotatably mount said impeller thereon, wherein a part of said drive shaft is inside said pump housing and a remaining part of said drive shaft is outside said pump housing;
• a sleeve disposed on said drive shaft and having a plurality of grooves configured thereon;
• a bush disposed on said sleeve, wherein a cJearance is provided between said bush and said sleeve;
• a fluid arrestor disposed on said sleeve; and
• an expeller disposed on said sleeve, wherein said expeller, said fluid arrestor, said sleeve and said bush are adapted to provide sealing between said drive shaft and said pump housing.
2. The pump as claimed in claim 1, further comprising a stuffing box chamber having a cavity for collection of fluid therein.
3. The pump as claimed in claim 1, wherein said impeller has at least one back vane.

4. The pump as claimed in claim 1, further comprising a connecting tube functionally coupled to said expeller.