FORM 2
THE PATENTS ACT, 1970
(39 of 1970) As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A grease-packed bearing retaining mechanism and end suction pumps, thereof.
APPLICANT:
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Ingle Vijay Pandurang and Susar Pandhari Namdeo; both of Crompton Greaves Limited, Pumps Division, C-19, MIDC, Ahmednagar - 414 111, Maharashtra, India; both Indian Nationals.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION:
This invention relates to mechanical engineering and mechanical assemblies.
Particularly, this invention relates to pumps and bearings, thereof.
More particularly, this invention relates to end suction pumps and grease-packed bearings, thereof.
Specifically, this invention relates to a grease-packed bearing retaining mechanism and end suction pumps, thereof.
BACKGROUND OF THE INVENTION:
An end suction pump is, generally, a pump for drawing up a liquid by means of suction produced by impeller through centrifugal action. Typically, a single suction pump has its suction nozzle on the opposite side of the casing from the stuffing box and has the face of the suction nozzle perpendicular to the longitudinal axis of the shaft.
End suction pumps are used in applications such as water transfer, water supply, Irrigation, Agriculture, Water Boosting, Pressurized Systems, for both Engine Driven and Motor Driven. It may be used in the following applications: I. General Water Supply applications for Circulation of cooling and heating
building systems, water booster service, boiler feed, general circulation
service;

II. Agriculture / Food / Beverage applications for Irrigation, water supply, food processing, beverage processing, fertilizers;
III. Manufacturing applications for Pulp and paper fan pumps, plastic and rubber, metal and steel, pharmaceutical, paper mills, air wash, marine ballast service;
IV. Fire/ Disaster Relief applications for Fire fighting pumps, fire protection, flood control, disaster relief, military
V. Utilities such as Water/ Wastewater applications for Power generation
stations, dewatering, desalination, energy recovery turbines; and VI. Chemical/ Mining applications for Chemical plants, refineries, petroleum distribution, coal sites, ethynol glycol pumping.
This invention specifically relates to axial bearings and its movement restriction in the axial direction, thereof. These bearings are placed at both the axial ends of a shaft which is placed co-axial to a bearing bracket. The shaft includes a shoulder portion which contacts with the bearing. To prevent axial movement of the bearing, at least at one external operative edge of the shaft, a bearing cover is located which keeps the bearing in place between the bearing cover and the shaft shoulder. This cover is an axial disc arranged on or alongside the bearing shaft at both ends. This cover is a machined cast cover fastened to the bearing housing on both sides, used to restrict the axial movement of bearing on the shaft. This is the general practice used in end suction pump bearing bracket unit assembly.
This is an impractical assembly for several following reasons:
1. It involves the time consuming task like casting, machining, drilling of bearing cover;
2. To fasten it, adaptor needs to be tapped and face machining; and

3. Fasteners required fastening to an adaptor.
PRIOR ART:
GB723447 relates to a Bearing Retained in the Bolster by means of washer and circlip. GB723447 provides a circlip and washer configuration, which is different from the proposed invention. Also, GB723447 speaks about a footstep bearing and roller bearing as opposed to grease-packed bearing used in the end suction pump which is the subject of this specification.
US6702468 relates to a Sliding bearing for a magnetically driven centrifugal pump. It uses sliding bearing as opposed to grease-packed ball bearing used in the end suction pump which is the subject of this specification. Also, End suction pump without bearing cover concept is not in existence.
CN1099104 relates to a Rolling bearing is replaced by sliding bearing. There is no mention of circlip and / or cast step and machined step in a manner as to avoid bearing cover.
GB980810 relates to an apparatus including a shaft rotatably mounted in a housing, and sealing means located within the housing for controlling leakage of fluid between the shaft and the housing. GB980810 specifically relates to the lubrication and sealing but retains the end cover.
Document, "Spheroidal Cast Iron Housings for Ball Bushings & Plain Bushings'"' relates to standard closed and adjustable ball bushings which are fitted to a housing using external circlips DIN 471 located in the circlip grooves on the exterior of the

ball bushing. This non patent literature describe the ball bushing and plain bushing as opposed to grease-packed ball bearing used in the end suction pump which is the subject of this specification.
Document, "BH0400 : Round Double Bearing Housing with Circtips" relates to the use of a step and circlip on either side of the bearing. This non patent literature deviates from the grease-packed ball bearing used in the end suction pump which is the subject of this specification.
OBJECTS OF THE INVENTION:
An object of the invention is to restrict the axial movement of a grease-packed bearing on a shaft.
Yet another object of the invention is to restrict the axial movement of a grease-packed bearing on a shaft which object is to be achieved by relatively reduced
machining.
Still another object of the invention is to restrict the axial movement of a grease-packed bearing on a shaft without the use of fasteners.
An additional object of the invention is to restrict the axial movement of a grease-packed bearing on a shaft without the use of end covers, thereby resulting in weight reduction.

Yet an additional object of the invention is to provide a mechanism to restrict the axial movement of a grease-packed bearing on a shaft, which results in overall cost reduction.
Still an additional object of the invention is to provide a fastening mechanism to restrict the axial movement of a grease-packed bearing on a shaft, which results in a compact design.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a grease-packed bearing retaining mechanism for a shaft with a medial axial end and a lateral axial end with bearings at each of said ends, said mechanism comprises:
a. medial retaining mechanism comprising a machined step on said shaft, at its
medial end, which forms a shoulder on said shaft and a circlip adapted to be
fitted such that it rests against said machined shoulder in a bearing housing
such that said circlip arrests axial movement of said bearing; and
b. lateral retaining mechanism comprising a machined step on said shaft, at its
lateral end, which forms a shoulder on said shaft and a cast step in a bearing
housing which complements said machined step on the lateral side such that
the steps fit together to arrest axial sliding of the bearing.
According to this invention, there is also provided an end suction pump comprising a grease-packed bearing retaining mechanism for a shaft with a medial axial end and a lateral axial end with bearings at each of said ends, said mechanism comprises:

i. medial retaining mechanism comprising a machined step on said shaft, at its medial end, which forms a shoulder on said shaft and a circlip adapted to be fitted such that it rests against said machined shoulder in a bearing housing such that said circlip arrests axial movement of said bearing; and
ii. lateral retaining mechanism comprising a machined step on said shaft, at its lateral end, which forms a shoulder on said shaft and a cast step in a bearing housing which complements said machined step on the lateral side such that the steps fit together to arrest axial sliding of the bearing.
Typically, said bearing is a grease-packed bearing.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a sectional view of a portion of an end suction pump with a shaft and bearing along with bearing covers;
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a sectional view of a portion of an end suction pump with a shaft and bearing along with bearing retaining mechanism.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a sectional view of a portion of an end suction pump with a shaft and bearing along with bearing covers.

In a motor or an assembly such as end suction pump bearing bracket assembly (100), there is provided a shaft (12) which rotates in a bearing housing. There are bearings (14) provided at either end of the shaft or at the shoulder locations of the shaft. The shaft may extend beyond these shoulder locations. These bearings are supported by bearing brackets (16) in order to prevent their radial slipping. In order to restrain their axial movement so that they remain in communication with the shoulder of the shaft, bearing covers (18) are provided at either ends which exert contra-axial pressure to retain the bearing position. The bearing covers are held in place by means of bolts (19) or similar fastening mechanisms. The limitations and disadvantages, of these bearing covers are explained, earlier, in this specification.
According to this invention, there is provided a grease-packed bearing retaining mechanism and end suction pumps, thereof.
Figure 2 illustrates a sectional view of a portion of an end suction pump with a shaft and bearing along with bearing retaining mechanism.
The shaft includes a medial shoulder which is inside the pump assembly and an lateral shoulder which is at the outer side of the pump assembly. Hence, there are two sets of bearings; one for the medial shoulder and one for the lateral shoulder. The bearings improve stiffness and minimize staff deflection. Also, they aid in smooth rotation of the shaft. In order to curb, the axial displacement of the shaft, a retaining mechanism is provided; one at the medial end and one at the lateral end.
The bearing is, typically, a grease-packed bearing.

In accordance with an embodiment of this invention, the medial retaining mechanism comprises a machined step on a shaft (12), at its medial end, which forms a shoulder on the shaft. It further comprises a circlip (22) adapted to be fitted such that it rests against the machined shoulder of the shaft in the bearing housing (16). This circlip arrests the axial sliding of bearing.
In accordance with another embodiment of this invention, the lateral retaining mechanism comprises a machined step on a shaft (12), at its lateral end, which forms a shoulder on the shaft. It further comprises a cast step (24) in a housing which complements the machined step on the lateral side such that the steps fit together to arrest axial sliding of the bearing.
The proposed invention, of CG, relates to a grease-packed bearing having two axial ends; a Right Hand Side (RHS) end or a medial end, and a Left Hand Side (LHS) end or a lateral end. On the RHS, there is a machine step in a shaft and a circlip which prevents axial movement of the bearing. On the LHS, there is a machine step in a shaft and a cast step in a housing which complement each other in order to prevent axial movement of the bearing.
The inventive step of this invention results in the technical advancement of eliminating bearing cover and associated machining operation due to the aforementioned structural changes, and achieving arresting of axial motion. It also results in economic significance of reducing the machining, weight, and ultimately savings in cost.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent

to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and 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 grease-packed bearing retaining mechanism for a shaft with a medial axial end and a lateral axial end with bearings at each of said ends, said mechanism comprising;
a. medial retaining mechanism comprising a machined step on said shaft, at
its medial end, which forms a shoulder on said shaft and a circlip adapted
to be fitted such that it rests against said machined shoulder in a bearing
housing such that said circlip arrests axial movement of said bearing; and
b. lateral retaining mechanism comprising a machined step on said shaft, at its
lateral end, which forms a shoulder on said shaft and a cast step in a
bearing housing which complements said Machined step on the lateral side
such that the steps fit together to arrest axial sliding of the bearing.
2. A retaining mechanism as claimed in claim 1 wherein, said bearing is a grease-packed bearing.
3. An end suction pump comprising a grease-packed bearing retaining mechanism for a shaft with a medial axial end and a lateral axial end with bearings at each of said ends, said mechanism Comprising:
i. medial retaining mechanism comprising a machined step on said shaft, at its medial end, which forms a shoulder on said shaft and a circlip adapted to be fitted such that it rests against said machinecl shoulder in a bearing housing such that said circlip arrests axial movement of said bearing; and
ii. lateral retaining mechanism comprising a machined step on said shaft, at its lateral end, which forms a shoulder on said shaft and a cast step in a bearing

housing which complements said machined step on the lateral side such that the steps fit together to arrest axial sliding of the bearing.
4. An end suction pump as claimed in claim 3 wherein, said bearing is a grease-packed bearing.