FIELD OF THE INVENTION
[001] The present invention relates generally to a Brush Less DC (BLDC) Motor.
More particularly, the present invention relates to a BLDC motor for ceiling fan,
whose lamination is common for TPW (Table, wall and Pedestal) & Ceiling Fan.
BACKGROUND OF THE INVENTION
[002] Brushless DC electric motor (BLDC motors, BL motors) also known as
electronically commutated motors (ECMs, EC motors), or synchronous DC
motors, are synchronous motors powered by DC electricity via an inverter or
switching power supply which produces an AC electric current to drive each
phase of the motor via a closed loop controller. The controller provides pulses of
current to the motor windings that control the speed and torque of the motor.
[003] Ceiling fans are generally induction motor driven or BLDC (Brush Less
Direct Current) motor driven. BLDC motor driven ceiling fans are preferred as
they have advantages like reduced power consumption, higher performance and
controllability and increased life.
[004] The existing ceiling fans with BLDC motors have a bigger size having a
diameter of 200mm of the ceiling fan motor and is heavier in size. Due to the size
and weight of the motor it becomes difficult to install and maintain the motor.
[005] Further, the large size also results in the usage of more material like copper
for winding and magnets for the motor.
[006] Currently, the available BLDC motor ceiling fans having a diameter of 200
mm and sweep/size of 1200 mm have power rating of 32 Watts with air delivery
of 220 m3/min and speed of 320 rpm.
[007] However there is a drawback with the size of current BLDC motor as it
can only be used for ceiling fans and for use with TPW fans, a separate smaller
BLDC motor has to be used.

[008] Further, if the size of the BLDC motor is reduced and is made common
lamination for ceiling as well as TPW fans.
[009] Hence, there is a need for a smaller BLDC motor which is common
lamination for both ceiling and TPW fans and is lighter in weight.
OBJECTS OF THE INVENTION
[0010] It is therefore an object of the present invention to manufacture a light
weight and cost effective small BLDC ceiling fan motor.
[0011] Another object of the present invention is to manufacture a small BLDC
ceiling fan motor whose output performance is similar to existing BLDC ceiling fan
motor of bigger size.
[0012] Yet another object of the present invention is to manufacture a small BLDC
ceiling fan motor whose lamination is common for ceiling and TPW fan which leads
to increase productivity and reduce component cost.
[0013] Yet another object of the present invention is to make sleek and slim ceiling
fan.
SUMMARY OF THE INVENTION
[0014] According to the present invention, the design optimized, small BLDC
Ceiling fan motor having a diameter of approx. 80mm can run the exiting
48”Ceiling fan blade and delivery the same air delivery as existing ceiling fan.
[0015] The same lamination can use for ceiling & TPW fan BLDC motor.
BRIEF DESCRIPTIONS OF THE ACCOMPANYING DRAWINGS
[0016] The above brief description, as well as further objects, features and
advantages, of the present invention can be fully appreciated by reference to the
following detailed description. These features of the present invention will
become more apparent upon reference to the drawings, wherein:

Fig. 1: BLDC motor according to the present invention
Fig. 2: Method of winding of BLDC motor according to the present invention
DETAIL DESCRIPTION OF THE INVENTION
[0017] The present invention will be described in detail below with reference to
an embodiment as shown in the drawing.
[0018] Ref. to Fig 1, small BLDC motor (100) for ceiling fan is disclosed. Said
BLDC motor (100) comprises a number of stator poles (10) surrounded by a
number of magnets (20) housed inside a magnet ring housing (30).
[0019] Said BLDC motor (100) for ceiling fan, according to the present invention,
has a stator pole (10) combination of 12 and the rotor pole combination (magnetic
poles) (20) of 10-34 numbers of magnets. Depending upon the number of said
magnets (20) the factors such the frequency, torque, rise in temperature of the
motor, power consumption etc. depends.
[0020] More number of magnets (20) results in the increase in the frequency of
said motor (100) which in turn results in less torque and less rise in the motor
temperature. This is very advantageous as it decreases the power
consumption/phase current and increases the life of said motor (100).
[0021] The above said combination is arranged in such a way that makes the
BLDC motor compact in size and yet the delivery output remains equivalent to the
existing BLDC motors.
[0022] The compact size of the BLDC motor is achieved by increasing the length
of the stator core to up to 25 mm and by using NdFeb magnets of thickness 1.8
mm instead of ferrite magnet of 10 mm thickness.
[0023] Ref. to Fig. 2, the delivery output of the said BLDC motor is achieved by
using the following winding method of said stator poles (10) in 12 coils 3 phase:


[0024] The invention has been described in an illustrative manner, and it is to be
understood that the terminology that has been used is intended to be in the nature
of words of description rather than of limitation. Obviously, many modifications
and variations of the present invention are possible in light of the above teachings.
It is therefore to be understood that within the specification, the reference
numerals are merely for convenience, and are not to be in any way limiting, the
invention may be practiced otherwise than is specifically described.

WE CLAIM:
1. A BLDC motor (100) for ceiling fan comprising:
a number of stator poles (10); and
a number of magnets (20) housed inside a magnet ring housing
(30);
characterized that said stator poles (10) are surrounded by said
magnets (20) to produce said BLDC motor (100) for ceiling fan.
2. The BLDC motor (100) as claimed in claim 1, wherein number of said
stator poles (10) is 10.
3. The BLDC motor (100) as claimed in claim 1, wherein number of said
magnets (20) is between 10 and 34.
4. The BLDC motor (100) as claimed in claim 1, wherein the length of stator
poles (10) is 25to 30mm and thickness of said magnet (20) is 1.8mmin
with NdFeb , 9mm with ferrite material.
5. The BLDC motor (100) as claimed in claim 1, wherein said magnets (20)
are NdFeb magnets of N35 grade & ferrite.
6. The BLDC motor (100) as claimed in claim 1, wherein said Lamination
(100) can be used for ceiling fans, table fan, wall fan and pedestal fan.