Title of Invention

A MULTI-POLE STATOR FOR A PERMANENT MAGNET GENERATOR

Abstract A multi-pole stator for a permanent magnet generator wherein the lateral surface of each pole is tapered, narrowing towards the center of the stator core, so as to be radially or substantially radially, disposed with respect to the said centre, whereby each said pole enables a larger number of turns of the stator winding to be accommodated on each said pole.
Full Text This invention relates to a multi-pole stator for a permanent magnet generator. Depending on the application, the rotor can be inside or outside the stator.
The consideration for the number of poles on the stator or rotor depends mainly on the output requirement. These types of generators are largely used on two/three wheelers and general purpose engines for generation of electric power.
The desired output characteristics, that is, output current with respect to rpm of rotation is such that for a given output rating, the output is high at low rpm and a saturated output at higher rpm.
Whilst the basic output depends on magnet strength, the number of poles on stator and rotor, the output saturation characteristic largely depends on the number of turns. For a given output current rating and chosen wire diameter, the more the number of turns which can be accommodated in the stator, the closer the characteristic towards the desired output.
With the foregoing factors in view, this invention proposes a multi-pole stator for a permanent magnet generator, which enables a higher number of turns to be provided on the poles thereby achieving an output close to the desired characteristic.

The foregoing feature of this invention may also be employed to reduce the number of poles that may otherwise be required on the stator. This also results in ease of manufacture.
Accordingly, in this invention relating to a multi-pole stator for a permanent magnet generator the lateral surface of each pole is tapered, narrowing towards the centre of the stator core, so as to be radially or substantially radially, disposed with respect to the said centre, whereby each said pole enables a larger number of turns of the stator winding to be accommodated on each said pole.
This invention will now be described in greater detail with reference to the accompanying drawings wherein
Fig.l illustrates a current (amps) output vs. speed characteristic, with two curves A and B pertaining to higher number of turns (desired characteristic) and lower number of turns respectively.
Fig.2 illustrates the known stator core with winding
Fig. 3 illustrates, by way of example, and not by way of limitation, the stator core with winding, according to one of possible embodiments of this invention.

The desired output characteristic is shown by the curve A in Fig. 1 which, for a given output current, pertains to high output at low rpm and saturated output at higher rpm (higher number of turns) unlike curve B which pertains to a situation in which higher the rpm, higher is the output (lower number of turns).
From Fig. 2 it will be observed that the conventional stator core pack structure is such that the number of turns T which can be accommodated is limited on account of space constraints, since if more number of turns are provided, the winding D tends to foul (by the coils touching each other) at the end E of each pole P.
From Fig. 3, however, it will be observed that the lateral surface S of each pole P is tapered, narrowing towards the centre C of the stator core, so as to be radially or substantially radially, disposed with respect to the said centre, whereby each said pole enables a larger number of turns V of the stator winding (than that possible in the case of poles with a non-tapering surface, such as the one illustrated in Fig.2) to be accommodated on each said pole.
The terms and expressions in this specification are of description and not of limitation, there being no intention in the use of such terms and expressions of excluding any equivalents of the features illustrated and described, but it is understood that

various other embodiments of the multi-pole stator proposed herein are possible without departing from the scope and ambit of this invention.


We Claim:
1. A multi-pole stator for a permanent magnet generator wherein the
lateral surface of each pole is tapered, narrowing towards the centre
of the stator core, so as to be radially or substantially radially,
disposed with respect to the said centre, whereby each said pole
enables a larger number of turns of the stator winding to be
accommodated on each said pole.
2. A multi-pole stator for a permanent magnet generator substantially
as herein described with reference to, and as illustrated in Fig.3 of
the accompanying drawings.
Dated this the 28th day of August 2000.

Documents:

0692-mas-2000 abstract.pdf

0692-mas-2000 claims-duplicate.pdf

0692-mas-2000 claims.pdf

0692-mas-2000 correspondence-others.pdf

0692-mas-2000 correspondence-po.pdf

0692-mas-2000 description (complete)-duplicate.pdf

0692-mas-2000 description (complete).pdf

0692-mas-2000 drawings.pdf

0692-mas-2000 form-1.pdf

0692-mas-2000 form-19.pdf

0692-mas-2000 form-26.pdf


Patent Number 215914
Indian Patent Application Number 692/MAS/2000
PG Journal Number 13/2008
Publication Date 31-Mar-2008
Grant Date 05-Mar-2008
Date of Filing 28-Aug-2000
Name of Patentee INDIA NIPPON ELECTRICALS LIMITED
Applicant Address HOSUR-THALI ROAD, ULIVEERANAPALLI, HOSUR - 635 114,
Inventors:
# Inventor's Name Inventor's Address
1 RAMAN UMASHANKAR INDIA NIPPON ELECTRICALS LIMITED, HOSUR-THALI ROAD, ULIVEERANAPALLI, HOSUR 635 114,
2 VENKATACHALAM CHANDRASEKAR INDIA NIPPON ELECTRICALS LIMITED, HOSUR-THALI ROAD, ULIVEERANAPALLI, HOSUR 635 114,
PCT International Classification Number H02K 3/12
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA