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
WIRE FORMED MOTOR ENCLOSURE AND END SHIELDS
APPLICANT
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Same Mahesh of Crompton Greaves Ltd, Industrial Design Centre, Global R&D, Crompton Greaves, Kanjurmarg (East), Mumbai- 400042 Maharashtra, India; an Indian National
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 the field of motors and motor assemblies.
Particularly, this invention relates to a wire formed motor enclosure with wire formed end shields.
BACKGROUND OF THE INVENTION:
An electric motor converts electrical energy into mechanical energy. It contains three main components; stator, rotor, and commutator. The rotor is the non-stationary part of a rotary motor, which rotates because the wires and magnetic field of the motor are arranged so that a torque is developed about the rotor's axis. The stator is the stationary part of a rotor system. The commutator is a rotary electrical switch that periodically reverses the current direction between the rotor and the external circuit. The rotor has a fanning action.
A motor is typically enclosed in a motor frame or a motor enclosure. According to the prior art, the frame or the enclosure was produced by circular bending of a flat rectangular sheet of metal. Then, a process of seam welding was carried out at the joint to form the motor frame or motor enclosure.
This process required the inclusion of two more further operations; 1) removal of oval-ness of the frame or enclosure; and 2) internal grinding of seam projection on inner face of motor frame or motor enclosure. These were time consuming and expensive procedures.
The enclosures of frames of a motor are subject to the following conditions for

providing a safe and efficient housing:
1) stress levels due to the working of the motor i.e. the rotary motion of the rotor in the stator and weight of the Stator and rotor;
2) excitation frequency of the rotor (in order to avoid resonance); and
3) temperature of operation of motor (due to heat dissipation).
It is important that the motor frame or motor enclosure be robust to take care of the above-mentioned conditions. It is simultaneously important that the robustness does not result in increase in weight of the frame.
OBJECTS OF THE INVENTION:
An object of the invention is to provide a motor frame or a motor enclosure which eliminates the procedures of oval-ness removal.
Another object of the invention is to provide a motor frame or a motor enclosure which eliminates the procedures of internal grinding of seam projection on its inner face
Yet another object of the invention is to provide a motor frame or a motor enclosure which provides improved heat transfer for the motor enclosed by the motor frame or motor enclosure.
Still another object of the invention is to provide a motor frame or a motor enclosure which makes stator insertion, within the motor frame or motor enclosure, easy.

An additional object of the invention is to provide a motor frame or a motor enclosure without any or with minimal tooling requirements.
Yet an additional object of the invention is to provide a motor frame or a motor enclosure wherein process cost reduction is achieved.
Still an additional object of the invention is to provide a motor frame or a motor enclosure such that there is ease of motor stator assembly.
Another additional object of the invention is to provide a motor frame or a motor enclosure which eliminates the procedure of casting.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a wire formed motor enclosure with wire formed end shields, said frame adapted to be wrapped around a motor, said frame comprises:
a. helically wound wires to form a pre-defined shape for covering a motor, said
helically wound wires forming a main body, said wires being wound to be of
pre-defined curvature, in that, the wires coil adjacent each other to form a
substantially cylindrical frame or enclosure; and
b. spirally wound wires adapted to form a first end disc and a second end disc
adapted to cover said main body at its axial ends.
Typically, said wire is a metal wire.
Preferably, said wire is a steel wire.

Typically, said pre-defined shape is a cylindrical shape with hollow within.
Typically, said enclosure comprising gluing material between two adjacent winding turns of said helically wound wires aiding in merger from outside of enclosure.
Typically, said enclosure comprising gluing material between two adjacent winding turns of said spirally wound wires aiding in merger from outside of enclosure.
Typically, said enclosure comprising suitably pre-formed wires in order to provide base support to said enclosure.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a first top view of the motor frame or motor enclosure of the prior art;
Figure 2 illustrates a second top view of the motor frame or motor enclosure of the prior art;
Figure 3 illustrates a first end (non drive end) view of a motor within a motor frame or motor enclosure of the prior art;
Figure 4 illustrates a second end (drive end) view of a motor within a motor frame or motor enclosure of the prior art;

Figure 5 illustrates a first end (non drive end) isometric view of a motor within a motor frame or motor enclosure of the prior art; and
Figure 6 illustrates a second end (drive end) isometric view of a motor within a motor frame or motor enclosure of the prior art.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 7 illustrates an isometric view of a motor frame or motor enclosure;
Figure 8 illustrates a cut-section view of a motor frame or motor enclosure;
Figure 9 illustrates a front view of a motor frame or motor enclosure;
Figure 10 illustrates a side view of a motor frame or motor enclosure;
Figure 11 illustrates a top view of a motor frame or motor enclosure;
Figure 12 illustrates a wire formed main casing which forms the main body of the motor frame or motor enclosure of Figure 1;
Figure 13 illustrates a wire formed end shield of the motor frame or motor enclosure of Figure 1; and
Figure 14 illustrates a wire formed base of the motor frame or motor enclosure of Figure 1.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a first top view of the motor frame or motor enclosure of the prior art.
Figure 2 illustrates a second top view of the motor frame or motor enclosure of the prior art.
Figure 3 illustrates a first end (non drive end) view of a motor within a motor frame or motor enclosure of the prior art.
Figure 4 illustrates a second end (drive end) view of a motor within a motor frame or motor enclosure of the prior art.
Figure 5 illustrates a first end (non drive end) isometric view of a motor within a motor frame or motor enclosure of the prior art.
Figure 6 illustrates a second end (drive end) isometric view of a motor within a motor frame or motor enclosure of the prior art.
A motor (10) is typically enclosed in a motor frame or a motor enclosure (12). According to the prior art, the frame or the enclosure was produced by circular bending of a flat rectangular sheet of metal (15). Then, a process of seam welding was carried out at the joint to form the motor frame or motor enclosure. The formed seam is referenced by numeral 14 in the accompanying drawings of the prior art. The foot of the metal, referenced by numeral 16, is seen in the accompanying drawings of the prior art. Reference numeral 22 refers to the drive

end of the motor. Reference numeral 24 refers to the non drive end of the motor. The motor is a shaft (26) mounted motor.
This process required the inclusion of two more further operations; 1) removal of oval-ness of the frame or enclosure; and 2) internal grinding of seam projection on inner face of motor frame or motor enclosure. These were time consuming and expensive procedures.
According to this invention, there is provided a wire formed motor enclosure with wire formed end shields.
Figure 7 illustrates an isometric view of a motor frame or motor enclosure, according to this invention.
Figure 8 illustrates a cut-section view of a motor frame or motor enclosure, according to this invention.
Figure 9 illustrates a front view of a motor frame or motor enclosure, according to this invention.
Figure 10 illustrates a side view of a motor frame or motor enclosure, according to this invention.
Figure 11 illustrates a top view of a motor frame or motor enclosure, according to this invention.
Figure 12 illustrates a wire formed main casing which forms the main body of the motor frame or motor enclosure of Figure 1 of the accompanying drawings.

Figure 13 illustrates a wire formed end shield of the motor frame or motor enclosure of Figure 1 of the accompanying drawings.
Figure 14 illustrates a wire formed base of the motor frame or motor enclosure of Figure 1 of the accompanying drawings.
In accordance with an embodiment of this invention, the motor frame or a motor enclosure, as referenced by reference numeral 100, is comprised of helically wound wires to form the shape of the motor frame or motor enclosure. The wire, typically, is a metal wire, and, preferably, is a steel wire. The wires are wound to be of pre-defined curvature, in that, the wires coil adjacent each other to form a substantially cylindrical frame or enclosure.
In accordance with a first embodiment of this invention, a main body (72) cylindrical part is formed by the helically wound wires which form the main body or main casing of motor.
In accordance with a second embodiment of this invention, a first end shield (drive end shield) (74) is formed by the helically wound wires. The end shield is made of spirally wound wires adapted to form a first end disc / shield adapted to cover said main body at its axial ends
In accordance with a third embodiment of this invention, a second end shield (non drive end shield) (76) is formed by the helically wound wires. The end shield is made of spirally wound wires adapted to form a second end disc / shield adapted to cover said main body at its axial ends

In accordance with another embodiment of this invention, the enclosure comprises suitably pre-formed wires in order to provide base support to said enclosure. This is represented by reference numeral 78 in Figure 14 of the accompanying drawings.
This motor frame or motor enclosure construction increases the surface area and aids in motor quick cooling.
If drip proofing feature is required by a motor to be enclosed in the motor frame or motor enclosure of this invention, then the same can be achieved by providing gluing material between two adjacent winding turns aiding in merger from outside of enclosure with a sacrifice of enclosure of inside hot air escape gap.
This motor frame or motor enclosure does not need any tooling and with a spring making machine, the required wound coil can be produced. This motor frame or motor enclosure imparts new novel wrapped bearing look to motor and generates a feel of low noise motor. Further, it also imparts forged look to motor compared to casted look and sheet metal look motor available in market and gives competitive edge over competing products.
Other advantage of having such enclosure is instead of a stator being pressed inside the enclosure as done in the motor assembly of the prior art, with this current motor frame or motor enclosure, the frame or enclosure can be pressed onto stator, avoiding risk of stator damage during heavy stator handling. Apart from this, there is one more reason to work out such enclosure which is related to end shield to sheet metal enclosure spigot based assembly. Sometimes, while manufacturing sheet metal motor enclosures of the prior art, the ovality was not properly removed.

Therefore, during end shield spigot based end shield and enclosure assembly, some stretching of motor enclosure used to take place due to which reverse resultant forces used to act on motor enclosure due to spring back of sheet metal, and motor enclosure used to lose its seating on end shield spigot, which used to be evident when tie rods of entire motor assembly used get removed. The current invention of the motor frame and motor enclosure avoids the problems of ovality.
The technical advancement of this invention lies in provisioning a motor frame, which is a wire formed motor frame. The problem of ovality is solved. There is additional heat dissipation due to air pockets between adjacent coils of the wire. Problem of seam is resolved. Extra steps of 1) removal of oval-ness of the frame or enclosure; and 2) internal grinding of seam projection on inner face of motor frame or motor enclosure; are eliminated. Frictional force of insertion of stator in the motor frame or motor enclosure is reduced.
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 wire formed motor enclosure with wire formed end shields, said frame
adapted to be wrapped around a motor, said frame comprising:
a. helically wound wires to form a pre-defined shape for covering a motor,
said helically wound wires forming a main body, said wires being
wound to be of pre-defined curvature, in that, the wires coil adjacent
each other to form a substantially cylindrical frame or enclosure; and
b. spirally wound wires adapted to form a first end disc and a second end
disc adapted to cover said main body at its axial ends.
2. The wire formed motor enclosure as claimed in claim 1, wherein said wire is a metal wire.
3. The wire formed motor enclosure as claimed in claim 1, wherein said wire is a steel wire.
4. The wire formed motor enclosure as claimed in claim 1, wherein said predefined shape is a cylindrical shape with hollow within.
5. The wire formed motor enclosure as claimed in claim 1, wherein said enclosure comprising gluing material between two adjacent winding turns of said helically wound wires aiding in merger from outside of enclosure.
6. The wire formed motor enclosure as claimed in claim 1, wherein said enclosure comprising gluing material between two adjacent winding turns of said spirally wound wires aiding in merger from outside of enclosure.

7. The wire formed motor enclosure as claimed in claim 1, wherein said enclosure comprising suitably pre-formed wires in order to provide base support to said enclosure.