The present invention generally relates to a ceiling fan running using an induction
motor. More specifically, the present invention is related to arrangement of bearing
assembly in a ceiling fan.
5
BACKGROUND OF THE INVENTION
The subject matter discussed in the background section should not be assumed to
be prior art merely as a result of its mention in the background section. Similarly, a
10 problem mentioned in the background section or associated with the subject matter
of the background section should not be assumed to have been previously
recognized in the prior art. The subject matter in the background section merely
represents different approaches, which in and of themselves may also correspond
to implementations of the claimed technology.
15
A motor of a ceiling fan is typically an Alternating Current (AC) induction motor.
The motor includes a stator assembly present around a shaft (axle). Further, a rotor
is present around the stator assembly. Bearings are generally used to hold the stator
assembly on the shaft.
20
Figure 1 shows cut section diagram of a conventional motor assembly (100) of a
ceiling fan, according to prior art. As illustrated, the motor assembly (100)
comprises a shaft (102), a stator (104) present around the shaft (102), and a rotor
(106) present around the stator (104). Further, ribs (108) are used to support the
25 rotor (106) from both sides. Specifically, the rotor (106) is sandwiched between the
ribs (108) present between a top cover (110) and a bottom cover (112). The top
cover (110) and the bottom cover (112) enclose motor of the ceiling fan. A first
bearing (114) and a second bearing (116) are used to support the shaft (102) of the
motor. The first bearing (114) is present on an upper side of the motor and is
30 mounted along the top cover (110). Further, the second bearing (116) is present on
a lower side of the motor and is mounted along the bottom cover (112).
3
As described above, in reference to Figure 1, conventional ceiling fans employ dual
bearing support for eliminating dynamic imbalance that induces fan wobbling and
vibrations in induction motors of the ceiling fans. Usage of such dual bearing
5 support increases cost of a ceiling fan. In addition, configuration of rotor in an
induction motor is complicated and the assembling of top cover and bottom cover
is difficult, which further increases cost of a ceiling fan. Precision required for
production and installation of motor parts is also very high, specifically for
maintaining coaxiality of the top cover and the bottom cover. Further, the top cover
10 and the bottom cover are made of metals such as aluminium, and usage of such
metals add to cost of the ceiling fans.
Thus, there remains a need of an improved design of motor assembly of ceiling fans
that requires easy manufacturing and assembling, and reduces overall cost of the
15 ceiling fans.
OBJECTS OF THE INVENTION
A general objective of the invention is to provide a single sided bearing support for
20 a motor of a ceiling fan.
Another objective of the invention is to reduce overall cost of a ceiling fan.
Yet another objective of the invention is to solve engineering challenges like
25 imbalance, vibrations, and wobbling induced in an induction motor.
Still another objective of the invention is to eliminate the problem of concentricity
mismatch between top cover and bottom cover of a motor of a ceiling fan.
30
4
SUMMARY OF THE INVENTION
This summary is provided to introduce aspects related to a ceiling fan and an
induction motor used in a ceiling fan, and the aspects are further described below
in the detailed description. This summary is not intended to identify essential
5 features of the claimed subject matter nor is it intended for use in determining or
limiting the scope of the claimed subject matter.
In one embodiment, the ceiling fan comprises a motor, such as an induction motor.
The motor comprises a shaft wound with a stator core, and a rotor present around
10 the stator core. The motor is enclosed within a housing comprising a top cover and
a bottom cover, such that the top cover of the housing rests over a ball bearing
mounted on the shaft. The motor may further comprise multiple ball bearings
mounted at different levels on the shaft to support the top cover. The rotor is secured
with the top cover using one of rivets, dowel pins, screws, and bolts.
15
In one embodiment, the bottom cover is made of a plastic, specifically engineering
plastics. Further, other material such as Acrylonitrile Butadiene Styrene (ABS),
Polyphenylene Sulphide (PPS), Polyvinyl Chloride (PVC), High-Density
Polyethylene (HDPE), Polyethylene Terephthalate (PET), Polypropylene,
20 Polystyrene, and Polycarbonate could also be used to manufacture the bottom
cover.
In one embodiment, the rotor comprises a plurality of blades or fins secured to the
top cover of the housing.
25
Other aspects and advantages of the invention will become apparent from the
following description, taken in conjunction with the accompanying drawings,
illustrating by way of example the principles of the invention.
30
BRIEF DESCRIPTION OF THE DRAWINGS
5
The accompanying drawings constitute a part of the description and are used to
provide a further understanding of the present invention.
Figure 1 illustrates cut section diagram of a conventional motor assembly of a
5 ceiling fan, in accordance with prior art.
Figure 2 illustrates cut section diagram of a motor assembly of a ceiling fan, in
accordance with an embodiment of the present invention.
10
DETAILED DESCRIPTION OF THE INVENTION
The detailed description set forth below in connection with the appended drawings
is intended as a description of various embodiments of the present invention and is
not intended to represent the only embodiments in which the present invention may
15 be practiced. Each embodiment described in this disclosure is provided merely as
an example or illustration of the present invention, and should not necessarily be
construed as preferred or advantageous over other embodiments. The detailed
description includes specific details for the purpose of providing a thorough
understanding of the present invention. However, it will be apparent to those skilled
20 in the art that the present invention may be practiced without these specific details.
The present invention pertains to a ceiling fan. More specifically, the present
invention makes use of single sided bearing support for an induction motor used in
a ceiling fan.
25
Figure 2 illustrates a cut section diagram of a proposed motor assembly (200) of a
ceiling fan, in accordance with the embodiment of the present invention. As
illustrated, the motor assembly (200) may comprise a shaft (202) wound with a
stator core (204). A rotor (206) may be present around the stator core (204). A motor
30 of the ceiling fan may be enclosed within a housing made of a top cover (210) and
a bottom cover (212). The top cover (210) of the housing may rest over a ball
6
bearing (208) mounted on the shaft (202). Blades may be secured to the top cover
(210) of the housing.
In the above described manner, usage of a single bearing support in the motor
5 assembly (200) would bring down the cost of ceiling fans. Further, because bearing
support is not used on bottom portion of the motor assembly (200), there does not
remain a need to maintain coaxiality of the bottom cover (212) with the top cover
(210). For such reason, the bottom cover (212) could be made of a cheaper material
such as plastic, instead of a metal. Engineering plastics may be used to manufacture
10 the bottom cover (212). Further, other materials such as Acrylonitrile Butadiene
Styrene (ABS), Polyphenylene Sulphide (PPS), Polyvinyl Chloride (PVC), HighDensity Polyethylene (HDPE), Polyethylene Terephthalate (PET), Polypropylene,
Polystyrene, and Polycarbonate may also be used to manufacture the bottom cover
(212). Usage of plastic instead of a metal for manufacturing the bottom cover (212)
15 would also bring down overall cost of the ceiling fans. With usage of plastic for
manufacturing the bottom cover (212) would also assist in avoiding the costs
associated with die casting of aluminium and post processing costs associated with
machining and painting of bottom covers made using aluminium.
20 In accordance with an embodiment of the present invention, the rotor (206) may be
fixed with the top cover (210) by a supporting member (214). The supporting
member (214) may be one of rivets, dowel pins, screws, and bolts. Thus, securing
the rotor (206) with the top cover (210) using the supporting member (214) instead
of the ribs provide a simple assembling mechanism which is also cost efficient.
25
In view of the above provided embodiments and their explanations, it is evident that
the present invention optimizes fan performance by using single sided bearing
30 support (on upper side) and eliminating usage of bottom side bearing support. The
ceiling fan using single sided bearing support for motor in accordance with the
7
present invention is further characterized by reduced cost and eliminates the
engineering challenges including dynamic imbalance, vibration, and wobbling.
Although implementations of a ceiling fan using a single end bearing support in an
5 induction motor has been described in language specific to structural features and/or
methods, it is to be understood that the appended claims are not necessarily limited
to the specific features or methods described. Rather, the specific features are
disclosed as examples of a ceiling fan using a single end bearing support in an
induction motor.

We Claim:

1. A ceiling fan comprising:
a motor assembly (200) comprising a shaft (202) wound with a stator core
5 (204), and a rotor (206) present around the stator core (204), wherein the
motor assembly (200) is enclosed within a housing comprising a top cover
(210) and a bottom cover (212), and wherein the top cover (210) of the
housing rests over a ball bearing (208) mounted on the shaft (202).
10 2. The ceiling fan as claimed in claim 1, wherein the motor assembly (200) is
an induction motor.
3. The ceiling fan as claimed in claim 1, wherein multiple ball bearings (208)
are mounted on the shaft (202) at different levels, to support the top cover
15 (210).
4. The ceiling fan as claimed in claim 1, wherein the rotor (206) is secured
with the top cover using one of rivets, dowel pins, screws, and bolts.
20 5. The ceiling fan as claimed in claim 1, wherein the bottom cover (212) is
made of a plastic.
6. The ceiling fan as claimed in claim 5, wherein the plastic is selected from a
group consisting of Engineering plastics, Acrylonitrile Butadiene Styrene
25 (ABS), Polyphenylene Sulphide (PPS), Polyvinyl Chloride (PVC), HighDensity Polyethylene (HDPE), Polyethylene Terephthalate (PET),
Polypropylene, Polystyrene, and Polycarbonate.
7. The ceiling fan as claimed in claim 1, wherein a plurality of blades are
30 secured to the top cover (210) of the housing.