Claims:We Claim:
1. An assembly of a Brushless Direct Current (BLDC) ceiling fan with a compact modular design of a plurality of electronic modules housed in an aluminium die casted enclosed motor housing, the ceiling fan comprising:
a Brushless Direct Current (BLDC) motor with a complete enclosed and non-ventilated motor housing with an upper cover (11) and bottom cover (10);
a Switch Mode Power Supply (SMPS) module (19) with an inbuilt overload and thermal protection;
a motor controller module (18) designed to drive 3 phases of motor winding (212) by measuring a permanent magnet rotor (17) position by sensing the generated back EMF into the windings (212).;
an infrared (IR) receiver module (14) exposed to user remote though an IR lens (13) integrated on bottom cover (10).

2. An assembly of claim 1, wherein the upper cover (11) and bottom cover (10) of the BLDC motor may hold the permanent magnet rotor (17) mounted on a shaft (22) via an upper bearing (16) and a lower bearing (15).

3. An assembly of claim 1, wherein the stator (21) of the BLDC motor comprises
injection moulded upper frame (213) and lower frame (214) further providing insulation for copper windings (212);
a configuration to hold the Switch Mode Power Supply (SMPS) module (19) and the motor controller module (18) along with electronics separator (20).

4. An assembly of claim 1, wherein the infrared (IR) receiver module (14) is mounted on injection moulded IR receiver holder (27) which is press fitted on lower end of the shaft (22) below lower bearing (15) and is exposed to user remote via an IR lens (13) mounted into the bottom cover (10).

5. An assembly of claim 1, wherein the motor controller module (18) which senses BEMF to measure rotor (17) position and energising the 3 phases of motor winding (212) in a sequence to run motor with desired speed and direction.

6. An assembly of claim 1, wherein a four wire bus passing through the shaft (22) is connecting infrared (IR) receiver module (14) with motor controller module (18) which in turn powered by the SMPS module (19).

7. An assembly of claim 1, wherein raised turrets (203) with clearance step are used to align and hold the SMPS module (19) on electronics spacer (20) and further raised turrets (202) are used to align and hold motor controller module (18) on electronics spacer (20).

8. An assembly of claim 7, wherein a plurality of screw turrets (201) are employed to tighten stator upper insulator (213) and electronic spacer (20) together further enabling assembly of the SMPS module (19), motor controller module (18) and stator (21) together.

9. An assembly of claim 1, wherein a bottom cage (28) below lower bearing (15) in bottom cover (10) provides a platform to mount IR lens (13) and to occupy IR receiver module (14) and IR receiver holder (27).

10. An assembly of claim 9, wherein the plurality of raised turrets (272) may be designed to lock IR receiver module (14) when pressed into the bottom face of IR receiver holder (27), further IR receiver holder (27) designed with gripping element (271) which may lock with shaft (22) when slide through the lower hole of the shaft (22).

11. An assembly of claim 9, wherein plurality of raised turrets (131) on IR lens (13) are aligned with mounting holes in the bottom cage (28) on bottom cover, so the IR lens (13) may be pushed vertically upward and locked at the centre of bottom cover (10).
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
(As Amended by Patents Amendment Rules-2006)

COMPLETE SPECIFICATION

(See Section 10 and Rule 13)

Title of invention:
A BRUSHLESS DIRECT CURRENT CEILING FAN

APPLICANT:
Atomberg Technologies Pvt Ltd,
EL-111, Electronic zone, MIDC,
Mahape, Navi Mumbai- 400710,
Maharashtra, India.

The following specification particularly describes the invention and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application does not claim priority from any other patent application(s).
TECHNICAL FIELD

[002] The present invention in general relates to an enclosed non ventilated ceiling fan. More particularly, the fan is driven by Brushless Direct Current (BLDC) motor with safe low output voltage Switching Mode Power Supply (SMPS).

BACKGROUND
[003] Most of the ceiling fans run on Alternating Current (AC) induction motor or Brushless Direct Current (BLDC) motor. AC induction motor operates directly from AC voltage line and is very inefficient wherein most of the losses are electric and are dissipated as heat inside the motor housing further also reducing life of motor bearings.

[004] BLDC motor has no mechanical brush for commutation of the windings. Commutation is deployed by help of electronics board comprising of switching mode power supply (SMPS) and motor controller. The electronic board is generally mounted as a single unit outside on the down rod in lower canopy or upper canopy exposing it to external environment. The mechanical vibrations induced in down rod during fan operation result into severe impact on electronic board life and functional stability. In such cases, if IR based remote control is used then line of sight of IR receiver is obstructed by fan blades or fan body itself resulting in poor remote connectivity.

[005] Long lead wires to motor induce electronic noise and reduce functional reliability. This problem is increased significantly where hall sensors are used inside motor housing to sense motor position as all wires have to come outside the motor to the electronic board. Assembly of electronic board to the fan down rod becomes very troublesome and time consuming, it not only increases number of components and hence cost but also lead to poor reliability. To accommodate electronic board and supporting fitments on down rod increased overall fan size and cost. Fitment of electronic board outside using hardware components on down rod might also add noise to fan operation.

[006] The present disclosure may eliminate all the long standing limitation not limited to the above described and provide a compact modular designed, high efficient BLDC motor equipped ceiling fan.

SUMMARY
[007] Before the present assembly and its components and its method of use is described, it is to be understood that this disclosure is not limited to the particular apparatus and its arrangement as described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure but may still be practicable within the scope of the invention as determined by claims. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in detecting or limiting the scope of the claimed subject matter.

[008] In an embodiment, an assembly of a Brushless Direct Current (BLDC) ceiling fan is described. The ceiling fan may comprise a compact modular design of a plurality of electronic modules housed in an aluminium die casted enclosed motor housing. The ceiling fan may further comprise a Brushless Direct Current (BLDC) motor with a complete enclosed and non-ventilated motor housing with an upper cover and bottom cover. The ceiling fan may further a Switch Mode Power Supply (SMPS) module with an inbuilt overload and thermal protection. The ceiling fan may further a motor controller module designed to energize copper windings by measuring motor position by sensing the generated back EMF into the windings. The ceiling fan may further an infrared receiver module exposed to user remote though a IR lens diffuser integrated on bottom cover.

BRIEF DESCRIPTION OF DRAWINGS

[009] The detailed description is described with reference to the accompanying Figures. In the Figures, components are identified by 2 right-most digits of reference number, however the left most digit in three digit numbers is used to provide further detailing of a component. The same numbers are used throughout the drawings to refer like features and components.

[0010] Figure 1A and 1B represents a brushless direct current ceiling fan in accordance with an embodiment of the present disclosure.

[0011] Figure 2 illustrates an exploded view of the assembly of the brushless direct current ceiling fan motor in accordance with an embodiment of the present disclosure.

[0012] Figure 3 illustrates an assembled cross sectional view of the brushless direct current ceiling fan in accordance with an embodiment of the present disclosure.

[0013] Figure 4A and 4B illustrate the assembly of motor stator with SMPS module and motor controller module with top view and side view respectively in accordance with an embodiment of the present disclosure.

[0014] Figure 5 illustrate the assembly of IR receiver module, IR receiver holder and shaft respectively in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0015] The present disclosure may provide a Brushless Direct Current (BLDC) motor ceiling fan design which may incorporate a modular design approach of a plurality of electronic components housed completely inside the fan motor housing. A motor controller may be enabled to sense rotor position by sensing the generated back Electromotive Force (EMF) into the windings which may further eliminate the need of hall sensors used inside the conventional BLDC motor fans resulting in less wiring, simple assembly and cost effective solution.
[0016] The present disclosure may further enable a completely enclosed and non-ventilated motor housing as very less heat is generated in BLDC motor. Such arrangement may provide protection to the electronic components and their sub-assemblies disposed inside the fan housing. The electronic sub assembly may comprise three parts:
• Low output voltage Switch Mode Power Supply (SMPS) module (19);
• Motor controller module (18); and
• Infrared (IR) receiver module (14).
[0017] Modular division of electronic subassembly in three parts has given many advantages in terms of easy integration inside fan housing with minimum number of parts and keeping motor housing compact. The IR receiver module (14) may be integrated at lower end of the shaft (22) below lower bearing (15) exposing it to user remote through IR lens (13). This may provide good line of sight between IR receiver module (14) and remote increasing the overall remote range.
[0018] Referring figure 1A and 1B a brushless direct current ceiling fan is illustrated in accordance with an embodiment of the present disclosure wherein Figure 1A describes the fan with isometric bottom view and Figure 1B describes the fan with isometric top view. Further referring Figure 2, an exploded view is described illustrating all electronic modules and a plurality of sub-assemblies. The ceiling fan BLDC motor may comprise an aluminium die casted motor housing having an upper cover (11) and a bottom cover (10) holding the permanent magnet rotor (17) mounted on the shaft (22) via upper bearing (16) and lower bearing (15). A plurality of blades (12) (three, five, six and the like) may be mounted radially on top of motor upper cover (11). A Stator (21) may comprise an injection moulded insulator upper frame (213) and lower frame (214) serving as an insulator for copper windings (212) and also is configured to hold SMPS module (19) and a motor controller module (18) along with electronics separator (20).
[0019] The ceiling fan may comprise an IR receiver module (14) mounted on injection moulded IR receiver holder (27) which may be press fitted on lower end of the shaft (22) below lower bearing (15) and is exposed to user remote through an IR lens (13) incorporated in the centre of bottom cover (10). Three phases of motor copper windings (212) are connected to motor controller module (18) which may be used to sense BEMF to measure rotor (17) position and energising the winding (212) in sequence to run motor with desired speed and direction. A four wire bus passing through the shaft (22) is connecting IR receiver module (14) with motor controller module (18) which in turn powered by SMPS module (19).
[0020] Referring Figure 3, a cross sectional view of an assembly of the ceiling fan is illustrated in accordance with an embodiment of the present subject matter. Figure 3 further illustrates an upper end of down rod (25) assembly with mounting shackle (32) by screw nut assembly (30). Upper canopy (26) and lower canopy (23) are mounted on down rod (25) as shown is Figure 3. Shaft (22) is mounted on down rod (25) by screw nut assembly (24). An AC input supply wire (31) is passing through the down rod (25) and going to motor through shaft (22). Upper bearing (16) is pressed in bearing sitting area and sufficient space is provided in top cover so that sufficient clearance is available for electronics components on SMPS module (19) and motor controller module (18) mounted on top of stator (21).
[0021] In an exemplary embodiment, the stator core (211) may comprise 24 CRNGO laminations with 18 slots interlocked into one another are winded with 22 SWG dual coated copper wire after mounting injection moulded insulator upper frame (213) and lower frame (214).
[0022] Rotor ring (171) holding seven permanent arc magnets (172) each radially magnetized half north and half south pole is making a 14 pole rotor. The Rotor may be press fitted in motor bottom cover (10) till rotor locking step. Lower bearing (15) is pressed on to the bearing sitting area in bottom cover (10).
[0023] Referring Figure 4A and 4B, the motor with SMPS module (19) and motor controller module (18) with top view and side view respectively is illustrated in accordance with an embodiment of the present disclosure. An electronic spacer (20) is resting on stator upper insulator frame (213). A plurality of raised screw turrets (201) are located at 120 degrees with respect to each other providing clearance between copper winding (212) and electronic modules. SMPS module (19) is aligned and mounted on to the electronic separator (20) using raised turrets (203). Similarly, raised turrets (202) are used to align and hold motor controller module (18) on electronics spacer (20). In an exemplary embodiment, three raised screw turrets (201) are then used to tighten stator upper insulator (213) and electronics spacer (20) together completing assembly of electronic modules on stator (21). This assembly of components are characterised such that they are assembled comparatively faster further reduce number of components and cost.
[0024] The three phases motor winding (212) may be terminated directly to the motor controller module (18) at motor controller output connector (183). Input AC power is supplied to SMPS module (19) through input connector (191). A stable 24V DC power is available at output connector (192) which is supplied to the motor controller module (18) through input connector (181). SMPS module (19) has inbuilt overload and thermal protection which might occur due to motor controller module (18) or stator winding (212) fault. The motor controller module (18) may measure magnet rotor (17) position by precisely sensing the induced back-EMF into the windings (212) and energise winding (212) in correct sequence to rotate motor with desired speed and direction. This advantageously eliminates Hall sensor and hence increase motor reliability further. Motor controller module (18) comprise of an on-board microcontroller integrated with firmware for protection logic against motor lock or excess load and abnormal conditions.
[0025] Referring Figure 5, an assembly of IR receiver module (14), IR receiver holder (27) and shaft (22) is illustrated in accordance with an embodiment of the present disclosure. A plurality of turrets (272) may be designed to lock IR receiver module (14) when pressed into the bottom face of IR receiver holder (27). The IR receiver holder (27) when enabled to slide into the lower hole of the shaft (22), holder gripping element (271) may lock with friction from inner wall of shaft (22). In an exemplary embodiment the IR receiver module (14) and IR receiver holder (27) design is compact so that diameter of assembly is lesser than shaft (22) outer diameter or lower bearing (15) inner diameter. Such arrangement may simplify the fan assembly and save assembly time. The IR receiver module (14) and IR receiver holder (27) assembly may be done to the motor shaft (22) before assembling motor upper cover (11) and bottom cover (10) together. In another exemplary embodiment, if the size of IR receiver module (14) and IR receiver holder (27) is larger than lower bearing (15) inner diameter then it can be installed only after final assembly of fan housing as lower bearing (15) has to pass through the shaft (22) while assembling the fan upper cover (11) and bottom cover (10). Now lower end of shaft (22) is accessible from bottom cage (28) in bottom cover (10) where IR lens (13) is mounted after installing IR receiver module (14) and IR receiver holder (27).
[0026] Referring exploded view of motor in figure 2, the IR lens (13) having three raised turrets (131) are aligned with mounting slots in the bottom cage (28) on bottom cover, so that the IR lens (13) may be pushed vertically upward and locked into the centre of bottom cover (10). The IR lens (13) at fan bottom centre increases remote range and also provides ingression protection to IR receiver module (14).
[0027] In an embodiment, the user may control fan via remote control, transmitted control signals are received by IR sensor (141) integrated on IR receiver module (14) mounted on the lower end of the shaft (22) directly behind the IR lens (13). Received signal is send to the motor controller module (18) via a four wire connection terminating at connector (182) on motor controller module (18), which in turn regulate motor speed and make indicator LED (142) integrated on IR receiver module (14) blink to acknowledge user on successful communication.

LIST OF COMPONENTS

• Upper cover (11)
• Bottom cover (10)
• Blades (12)
• Upper canopy (26)
• Lower canopy (23)
• Down rod (25)
• AC input wire (31)
• Shackle (32)
• Shackle mount screw assembly (30)
• Shackle – down rod screw assembly (29)
• Down rod – shaft screw assembly (24)
• Upper bearing (16)
• Lower bearing (15)
• Permanent magnet rotor (17)
• Permanent magnet (172)
• Rotor ring (171)
• Shaft (22)
• Stator (21)
• Stator core (211)
• Copper windings (212)
• Stator upper insulator frame (213)
• Stator lower insulator frame (214)
• Electronics separator (20)
• Stator insulator mounting screw turrets (201)
• Motor controller mounting screw turrets (202)
• SMPS mounting screw turrets (203)
• SMPS module (19)
• SMPS input 191)
• SMPS output (192)
• Motor controller module (18)
• Motor controller input (181)
• Motor controller output (183)
• IR module connector (182)
• IR lens (13)
• IR lens turrets (131)
• IR receiver module (14)
• IR receiver holder (27)
• IR holder turrets (272)
• Holder gripping element (271)
• IR receiver (141)
• Indicator LED (142)
• Bottom cage (28)