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 hub-less radial fan for an electrical rotating equipment and electrical rotating equipment with hub-less radial fan, thereof.
APPLICANTS :
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Pandya Ankit and Upadhyay Amarendra; both of Crompton Greaves Limited, Machine (M7)' Division, Industrial Area, MPAKVN, Mandideep - 462046, Madhya Pradesh, 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 the field of electrical rotating equipment and its cooling
parts, thereof.
Particularly, this invention relates to radial fans for electrical rotating equipment.
Specifically, this invention relates to a hub-less radial fan for an electrical rotating equipment and electrical rotating equipment with hub-less radial fan, thereof.
BACKGROUND OF THE INVENTION:
An 'electrical rotating machine' or a 'rotating electrical machine' is any form of apparatus, equipment, or system which has a rotating member and generates, converts, transforms, or modifies electric power. These include apparatus such as a motor, generator, or synchronous converter.
Essentially all of the world's electric power is produced by rotating electrical generators, and about 70% of this energy is consumed in driving electric motors. Electric machines are electromechanical energy converters; generators convert mechanical energy into electrical energy and motors convert electrical energy into mechanical energy.
The performance of an 'electrical rotating machine' or a 'rotating electrical machine' is defined by many characteristics. One such characteristic is the cooling quotient and ability of the components of the machine. A motor includes a rotating element called the rotor and a stationary element called the stator. The rotor temperature needs to be kept in check for such electrical rotating machines.

Efficient cooling of the rotor is an imperative parameter which decides its enhanced working coefficients.
Hence, a fan is generally installed on the rotor shaft which enables the hot air to be directed away from the motor towards the atmosphere or towards the heat exchanger mechanism associated with the motor.
This fan component, of the prior art, include a hub element and blades' element. The hub element is a central portion of the fan which aids in mounting of the fan to the rotor shaft. The blades' element is the peripheral or circumferential element of the fan which causes air turbulence when it is rotated by the hub. The blades may be of unidirectional discharge or of bidirectional discharge. These fans, of the prior art, have high centrifugal force because of their heavy structure contributed by the central hub element.
There is a need to reduce the weight of the fan assembly, thereby resulting in reduced relative force exerted by it.
OBJECTS OF THE INVENTION:
An object of the invention is to provide an 'electrical rotating machine' or a 'rotating electrical machine' with reduced weight.
Another object of the invention is to provide an 'electrical rotating machine' or a 'rotating electrical machine' with a compact design for an associated internal or external fan mounted on it.

Yet another object of the invention is to provide a hub-less fan for an 'electrical rotating machine' or a 'rotating electrical machine'.
Still another object of the invention is to provide a spoke-less fan for an 'electrical rotating machine' or a 'rotating electrical machine'.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a hub-less radial fan for an electrical rotating equipment, said fan comprises:
- a ring element characterized by a plurality of fan blades adapted to radially
extend from said ring, each of said fan blades including a proximal end
being attached to said ring, and a distal end being radially extending away
from said ring.
According to this invention, there is also provided an electrical rotating equipment with a hub-less radial fan, said fan comprises:
- a ring element characterized by a plurality of fan blades adapted to radially
extend from said ring, each of said fan blades including a proximal end
being attached to said ring, and a distal end being radially extending away
from said ring.
Typically, said ring is dimensioned to snug fit around a rotating element of said electrical equipment.
Typically, said blades are selected from a plurality of blade profiles.
Preferably, said fan is of unidirectional discharge characteristics.

Alternatively, said fan is of bidirectional discharge characteristics. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a fan of the prior art.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a hub-less radial fan; and
Figure 3 illustrates an exemplary blade profile for the hub-less radial fan.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a fan (100) of the prior art.
The fan includes a central hub (8) and fins (10) on the body extending from the hub. The fins provide air dispersion and the hub provides for locating the fan on to a shaft for support.
According to this invention, there is provided a hub-less radial fan for an electrical rotating equipment. According to this invention, there is also provided an electrical rotating equipment with hub-less radial fan.
Figure 2 illustrates a hub-less radial fan (200).
Figure 3 illustrates an exemplary blade profile for the hub-less radial fan.

In accordance with an embodiment of this invention, there is provided a ring (12). The ring is, preferably, dimensioned to snug fit around a rotor. The ring is adapted to be fitted around the non-drive end of a rotor where ventilation is required. In accordance with another embodiment of this invention, there are provided a plurality of fan blades (14) adapted to radially extend from said ring. Each fan blade includes a proximal end which is attached to the ring, and a distal end which is radially extending away from the ring. The blade profile may be selected from a plurality of blade profiles.
The ring and the fan form the fan assembly in total. The fans may be of unidirectional discharge characteristics or of bidirectional discharge characteristics.
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 hub-less radial fan for an electrical rotating equipment, said fan
comprising:
a ring element characterized by a plurality of fan blades adapted to radially extend from said ring, each of said fan blades including a proximal end being attached to said ring, and a distal end being radially extending away from said ring.
2. A fan as claimed in claim 1 wherein, said ring is dimensioned to snug fit around a rotating element of said electrical equipment.
3. A fan as claimed in claim 1 wherein, said blades are selected from a plurality of blade profiles.
4. A fan as claimed in claim 1 wherein, said fan is of unidirectional discharge characteristics.
5. A fan as claimed in claim 1 wherein, said fan is of bidirectional discharge characteristics.
6. An electrical rotating equipment with a hub-less radial fan, said fan comprising:
a ring element characterized by a plurality of fan blades adapted to radially extend from said ring, each of said fan blades including a proximal end being attached to said ring, and a distal end being radially extending away from said ring.

7. An electrical rotating equipment as claimed in claim 1 wherein, said ring is dimensioned to snug fit around a rotating element of said electrical equipment.
8. An electrical rotating equipment as claimed in claim 1 wherein, said blades are selected from a plurality of blade profiles.
9. An electrical rotating equipment as claimed in claim 1 wherein, said fan is of unidirectional discharge characteristics.
10. An electrical rotating equipment as claimed in claim 1 wherein, said fan is of bidirectional discharge characteristics.