FORM-2 THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL
Specification
(See section 10 and rule 13)


BEARING HOUSING OF THE PUMP
KIRLOSKAR BROTHERS LIMITED
an Indian Company
of Udyog Bhavan, Tilak Road, Pune 411 002,
Maharashtra, India

THE FOLLOWING SPEC IFICATION DESCRIBES THE INVENTION.
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FIELD OF THE INVENTION
This invention relates to a pump.
Particularly, this invention relates to the bearing housing of the pump.
INTRODUCTION:
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A pump is a device used to move liquids from any source location to another location for storage or consumption. Pumps work by using mechanical forces to push the fluid material, by physically lifting, by the force of compression or by centrifugal force.
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Pumps fall into two major groups called roto-dynamic pumps and positive displacement pumps. Roto-dynamic pumps are based on bladed impellers which rotate within the fluid to impart a tangential acceleration to the fluid and a consequent increase in the energy of the fluid. The purpose of the pump is toj convert this energy into pressure energy of the fluid to be used in the associated piping system.
A positive displacement pump causes a liquid of gas to move by trapping a fixed amount of fluid or gas and then forcing (displacing) that trapped volume into the discharge pipe.
In a roto-dynamic pump the impeller is located on the pump shaft and rotates at high speed. To reduce friction between the shaft and housing, ball
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bearings are used. Location and type of bearings used in a pump depends on the type, capacity, and design of the pump. In a centrifugal single stage pump the impeller is mounted on one end the pump shaft extending into the casing and two bearings are used to support the shaft on the other end. However in a multistage horizontal split case pump the impellers are in the mid portion of the shaft enclosed inside the pump casing. The bearings are normally provided as out-board bearings on either side in an extension of the lower half of the pump casing.
The bearings are designed to withstand radial and axial loads caused by the rotating impellers and are expected to provide long and trouble free service. However the bearings have to be replaced after the expected life cycle either during a preventive or break-down maintenance shutdown. Replacement of the bearings should not be time consuming and difficult. Also it should be possible to replace the bearings without dismantling the entire pump
assembly.
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The location of the impeller on the shaft is very critical as any error in
locating the impeller will lead to dynamic imbalance and incorrect clearance
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between the pump casing and impeller. A factory fitted impeller is
accurately located on the shaft and delivers the rated volumetric output at
various pressure ratings of the pump. It is difficult to maintain the accuracy
of fitment! of the impellers, if the entire rotary unit consisting of shaft,
impellers, shaft seals or glands has to be dismantled at site conditions for
replacement of bearings.
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In a conventional split case pump replacement of the bearings involve the following steps. The pump is first isolated from the pumping system to prevent spillage of fluid in the pipe line and the bearing housings are unbolted from the pump housing. Then the upper pump casing is opened and the entire rotating unit is taken out of the lower half of the pump along with the bearings and bearing housings. After opening the bearing covers the

inserts are

pushed back and a bearing puller is used to release the bearings

from the shaft.
This entire procedure is time consuming and care has to be taken to prevent damage to the rotating unit. Skilled work force is required to remove and refit the rotating unit as any error in fitment causes several problems like vibration leading to bearing damage and drop in hydraulic performance of the pump.
In view of the above difficulty there is a need to develop a better bearing housing for mounting the bearings of a split case pump.
OBJECTS OF THIS INVENTION;
One of the objects of this invention is to provide a bearing assembly for a
split case pump that can be dismantled and reassembled quickly.
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Another object of this invention is to provide a bearing assembly for a split case pump that can be dismantled and reassembled even by unskilled personnel.
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Yet another object of this invention is to provide a bearing assembly for a split case pump that can be dismantled and reassembled without affecting the hydraulic performance of the pump.
Yet another object of this invention is to provide a bearing assembly for a split case pump that can be dismantled and reassembled without the use of
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expensive tools.
Yet another object of this invention is to provide a bearing assembly for a split case pump that can be easily manufactured.
Yet another object of this invention is to provide a bearing assembly for a split case pump that is inexpensive to manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS:
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The invention will how be described with respect to the accompanying
drawings in which:
Figure 1 is a perspective view of a conventional bearing assembly for a split case pump;
Figure 2 is a perspective view of a split case pump, with conventional bearing assembly wherein upper half casing is partly removed;
Figure 3 is a perspective view of a split case pump, with conventional bearing assembly wherein upper half casing is fully removed;
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Figure 4 is a perspective view of a conventional bearing assembly for a split case pump with insert;
Figure 5 is a perspective view of a bearing assembly for a split case pump as per this invention; and
Figure 6 is a perspective view of an insert for the bearing assembly of this invention of figure 5.
DETAILED DESCRIPTION OF THE DRAWINGS:
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Referring to Figure 1 a conventional bearing assembly for a split case pump of the prior art is shown. Insert 12 is mounted on the lower half of the pump casing (not specifically numbered) by nut bolts 14. The bearing assembly 16 is bolted to the insert 12 by threaded bolts 18. To dismantle the bearing from the housing the insert mounting bolts 14 are unfastened to release the insert from the lower pump casing.
At this stage the upper half casing of the pump is unbolted from the lower half and lifted up (refer figure 2) and separated from the pump assembly (refer figure 3). Now the entire rotating Unit of the pump consisting of the shaft, impellers, case-wear rings, bearings along with bearing mounting bracket, bearing housing and inserts is lifted out of the lower casing 22 of
the pump.
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At this stage bearing housing cover of one end of the pump shaft (not specifically numbered) is unbolted and the bearing resting unit 24(refer
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figure 4) also called insert is pushed back with reference to the pump shaft by tapping. After pushing the insert sufficiently back a bearing puller (not specifically shown) is used to remove the bearing 26 from the pump shaft. The same procedure is repeated on the other end of the pump shaft to release the second bearing. New bearings are inserted in place and the entire procedure, as described above, is carried out in reverse order to complete the assembly of the pump.
Referring to figure 5 and 6, the bearing housing as per this invention is indicated generally by the reference numeral 100. The bearing resting unit 28 of this! invention is provided with two flat surfaces 30 diametrically opposite to each other. The dismantling procedure for replacing the bearings of the pump is simple and the need to dismantle the rotating unit of the pump is eliminated. First the bearing cover is unbolted and a bearing puller is mounted on the outer ray of the bearing at the flat surface area of the bearing rest unit. The bearing can now be removed from the pump shaft by the puller
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without unbolting the upper case and rotating unit. This work can be carried
out by even unskilled labour crew.
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While considerable emphasis has been placed herein on the various components of the preferred embodiment, it will be appreciated that many
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alterations ban be made and that many modifications can be made in the preferred embodiment 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
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the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

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Dated this 24th day of June 2008.
Mohan Dewan of R.K. Dewan&Co Applicants' Patent Attorneys

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