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 hazardous motor with internal cooling mechanism
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli,
Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Khatua Satyaranjan, of Crompton Greaves Ltd, machine (M7) Division, D-5 Industrial Area, MPAKVN, Mandideep-462046, Madhya Pradesh, 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.
Particularly, this invention relates to the field of flameproof motors. More particularly, this invention relates to a cooled flameproof motor.
BACKGROUND OF THE INVENTION:
A motor for electrical purposes, i.e. an electric motor, is a device which converts electrical energy to mechanical energy.
For industrial use, the ratings of motor may typically be very high. They may be placed in housings or frames. It contains two main components; stator, rotor. 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 rotor has a fanning action.
The external circuit of the motor relates to the exterior of the motor housing. The internal circuit of the motor relates to the interior of the motor housing.
In a flameproof motor, cooling in the internal circuit was only by churning of air. So for dissipation of heat of the motor, circulation of air inside the motor is not available. Due to lesser heat dissipation, the motors are derated to high extent.

PRIOR ART:
The prior art patent document US7633194 discloses the concept of cooling stator lamination stacks, having an outer periphery with outwardly projecting pins cooperating with a jacket surrounding the stack to provide a cooling space through inlet ports/extending grooves. However the heat transfer seems to be only by convection.
The prior art document US20100026109 discloses the heat pipes incorporated into the stator slot and on back iron ring which is in between the stator core & outer frame. Also, discloses that the heat pipes may be implemented in the ^ore/laminations of the stator. However the heat transfer seems to be only by convection.
Patent document EP1211782 discloses a plurality of fixing holes provided at the stator core which penetrates in the laminated stator cores. However, the purpose is for connecting stator-magnetic-pole-assembly and stator core using resin. However the heat transfer seems to be only by convection.
In the motor and motor frame of the prior art, there was no circulation path for internal air in the earlier motor and motor frame. There was no circulation path by which internal heat could be transferred to the surface. Hence, hot air was circulated, inadvertently, in the motor and motor housing, itself. Hence, heat dissipation was less. Improper or insufficient heat dissipation may lead to stresses in the motor housing.

Also, since a flameproof motor is a hazardous motor, the (heated) internal air cannot be exited out of the motor frame. There is a need for internal heating. Hence, there is a need to provide a motor and motor frame which obviates the limitations of the prior art.
Objects of the Invention:
An object of the invention is to provide improved or relatively increased heat dissipation with respect to a motor.
Another object of the invention is to provide a relatively safer and reliable flame proof motor.
Yet another object of the invention is to provide higher ratings for motor due to increased heat dissipation capacity.
Still another object of the invention is to avoid stresses in a motor housing due to inadvertent thermal changes.
Another object of the invention is to provide an electric motor which provides internal heat dissipation or internal cooling for internal heated air.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a hazardous motor with internal cooling mechanism, said motor including a motor housing adapted to envelope said motor, said motor housing having a framed assembly of two concentric fames with an internal frame surrounding said motor, said motor housing comprises:

a. one or more holes, on the periphery of motor stampings, in the motor inner
frame, said holes adapted to act as a path for the internal air to be let out of
the stampings of said motor; and
b. fans adapted to guide said heated air from said motor frame for heat
exchanging to cool said motor.
Typically, said motor frame includes an inner motor frame and a concentric external motor frame.
Typically, said motor frame includes an inner motor frame and a concentric external motor frame which blocking pieces provided in between said external frame and said internal frame, said blocking frame adapted to aid in directing heated air from said motor through the cut-out holes towards said fans.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in relation to the accompanying drawings, in
which:
Figure 1 illustrates a cut-sectional isometric view of the motor frame;
Figure 2 illustrates a front sectional view of the motor frame; and
Figure 3 illustrates a front view of the motor and motor frame.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
According to this invention, there is envisaged a hazardous motor with internal cooling mechanism.

Figure 1 illustrates a cut-sectional isometric view of the motor frame.
Figure 2 illustrates a front sectional view of the motor frame.
Figure 3 illustrates a front view of the motor and motor frame.
The motor is bound inside a framed assembly having two concentric fames. The internal frame (12) surrounds the motor and is closes to the motor that it envelopes.
To arrest the problem of heated air in a motor which has no path for circulation, in accordance with an embodiment of this invention, a plurality of holes (14), on the periphery of motor stampings, in the motor inner frame (12), are envisaged. These holes will act as a path for the internal air to be let out of the stampings but yet be inside the motor frame that is restricted by the motor outer frame (13). The heated air from the rotor side will flow through these holes.
In accordance with another embodiment of this invention, internal fans (16) are provided, preferably placed, in front of the holes (14), The heated air exiting the stampings through the holes is in direct communication with the internal fan(s). These fan(s) provide for cooling of the heated air. Thus, heated air can be cooled by convection. Blocking pieces (18) are provided in between the external frame (13) and the internal frame (12) which aids in directing the air dissipated from the motor through the cut-out holes (14) towards the fans (16).

The fans (16) may be located on either side of the motor and motor housing, preferably on the operative upper part of the motor and motor housing.
Heat will be transferred both by conduction and convection. Drastic improvement in heat dissipation will happen due to both mode of transfer.
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 hazardous motor with internal cooling mechanism, said motor including a motor housing adapted to envelope said motor, said motor housing having a framed assembly of two concentric fames with an internal frame surrounding said motor, said motor housing comprising:
a. one or more holes, on the periphery of motor stampings, in the motor inner
frame, said holes adapted to act as a path for the internal air to be let out of
the stampings of said motor; and
b. fans adapted to guide said heated air from said motor frame for heat
exchanging to cool said motor.
2. A motor and motor frame as claimed in claim 1 wherein, said motor frame includes an inner motor frame and a concentric external motor frame.
3. A motor and motor frame as claimed in claim 1 wherein, said motor frame includes an inner motor frame and a concentric external motor frame which blocking pieces provided in between said external frame and said internal frame, said blocking frame adapted to aid in directing heated air from said motor through the cut-out holes towards said fans