From DDL Wiki

Contents 1 Customer Needs 2 Function 3 FMEA 3.1 Components:

Customer Needs

The customer’s primary need is to cool a room by circulating air. More air circulation provides greater air movement and cooling potential. The fan’s noise level is a concern of the customer. Quiet operation, with little to no vibrations is preferred. The customer must also be able to adjust the fan’s rotational speed to best suit the surroundings. This allows for quieter, lower energy, operation when maximum air circulation is unnecessary. Another necessity is the ability to vary the direction of where air is being. This includes altering the vertical orientation as well as providing horizontal oscillation. The fan should also be safe for the user. This involves shielding the fan blades, while still allowing air to pass through. This shielding prevents objects and body parts from coming in contact with the blades. Fans are generally only used during warm times of the year. As a result they must be easy to move and store while not in use.

Function

An oscillating fan cools an area using forced convection thus increasing heat transfer. This is accomplished by spinning three plastic blades which circulates air in the desired direction. The blades are spun by an AC brushless motor, which is powered from a standard 120V wall outlet. The motor’s rotational speed can be adjusted by the user using a circular knob. The fan is also capable of horizontal oscillation. The user starts this movement by pushing a button at the top of the fan casing. This engages a gear train which spins a small plastic linkage. This linkage is connected to an aluminum bar which is attached to the casing. This simple mechanism translates circular motion to oscillatory horizontal motion. The gear train is powered by the same motor and shaft that spin the blades, thus requiring no additional motor.

FMEA

Item and Function Failure Mode Effects of Failure S Causes of Failure O Design Controls D RPN Recommended Action Responsibility and Deadline Actions Taken S O D RPN Motor/Shaft Inhibited Rotation Inefficient Operation 5Debris (e.g. dust) in Fan 4 Run Under Extreme Dust and Debris Conditions 2 40Filter, Accessibility for Cleaning, Better Protection of Rotating Parts Motor Housing - 53230 Swivel Mount Nut Stripping, Plastic Fracture Cannot Adjust Vertical Directoin Fan Cannot Effectively Circulate Air 8 Overtightening, Material Failure 3 Overtightened Screw, Force applied on Swivel Area 1 24 Use Torque Limited Fastening, Using Stronger Plastic Swivel - 8 2 1 16 Oscillation Button Dislocation of Button Cannot Toggle Oscillation 6 Stripped Gear, Button Disengaged 5 Stronger Gears, Improved Connection 2 60 Fatigue Testing Gears and Button - 6 3 2 36 Blade Cover Inhibited Rotation, Blade Fracture Complete Inoperable8 Penetration of Cover 4 Penetrate Repeatedly 1 32 Warning Label, Redesign Cover User - 8 3 1 24 Shaft Non-concentric Rotation Vibration and Noise 5 Broken Bearing, Unbalanced Weight, Shaft Non-Uniformity 2 Quality Control 3 30 Vibration Testing Assembly - 5 1 3 15 Electronics Short Circuit Completely Inoperable 8Exposure to Water 3 Water Exposure Testing 2 48Waterproof Housing of Electronics Housing - 81216

Components:

As part of the first stage of disassembly, we documented the inner workings prior to removing each individual component. The first image shows the shredder with the top removed and certain key components labeled. The second is a detailed close-up of the gear train. Refer to the table below for more details on individual components identified in these pictures.

The following table contains each individual part present in the product. A brief description of each part and its function will help determine whether any of the components can be refined for future designs to make it less expensive or possibly remove it all together. It can be also be seen that a large, important part of the system is purchased (the motor and electronics).

Part #	Part name	QTY	Function	Materials	Manufacturing Process	Picture
001	Front Fan Cover	1	Protect the user's body parts Protects fan blades Aesthetics	??	Merging of Extruded Parts
002	Threaded Cap for Blades	1	Holds blade unit in place Left handed threading to keep it from loosening	Plastic	Injection Molding	[[]]
003	Blade Unit	1	Circulates Air	Plastic	Injection Molding	[[]]
004	Set Screw	1	Centers Blades	Steel	Extrusion	[[Image:]]
005	Rear Plate Fastener	1	Fastens rear plate	Plastic	Injection Molding	[[Image:]]
006	Rear Fan Cover	1	Protect the user's body parts Protects fan blades Aesthetics	??	Merging of Extruded Parts	[[Image:]]
007	Motor Front Cover	1	Protect motor components	??	cast	[[Image:]]
008	Swivel Adjustment Knob	1	Adjusts DOF's of fan position	Plastic/Steel	Injection Molding/Extrusion	[[Image:]]
009	Nut for Swivel Adjustment Knob	1	Fastens bolt of adjustment knob	Steel	Stamped	[[Image:]]
010	Fan Head Coupling	1	Attaches fan head to stand	Plastic/Steel	Injection Molding/Extrusion	[[Image:]]
011	Speed Selection Knob	1	Turns on power Selects speed of fan Interfaces with switch	Plastic	Injection Molding	[[Image:]]
012	Switch	1	Turns on power Selects speed of fan Interfaces with speed selection knob	Plastic/Copper	Injection Molding/Stamped	[[Image:]]
013	Motor Housing	1	Covers Motor Shaft Electrical Components	Plastic	Injection Molding	[[Image:]]
014	Capacitor	1	Stores electrical potential energy	Plastic/Other	N/A	[[Image:]]
015	Electrial Wire	7	Connects electric components	Plastic/Copper	Drawn	[[Image:]]
016	Oscillation Gear Casing	1	Holds the gears that control oscillation	??	Cast	[[Image:]]
017	Gear Casing Cap	1	Protects gears	Plastic	Injection Molding	[[Image:]]
018	Oscillation Control Knob	1	Toggles oscillation mode	Plastic	Injection Molding	[[Image:]]
019	Transmission Gear	1	Transfers rotation from shaft to gear 1	Plastic	Injection Molding	[[Image:]]
020	Small Ball Bearing	1	Prevents free motion of transmission gear	Steel	Cast	[[Image:]]
021	Small Spring	1	Prevents free motion of transmission gear	Steel	Extrusion	[[Image:]]
022	Gear 1	31	Transfers rotation from transmission gear to gear 2	Plastic	Molded	[[Image:]]
023	Gear 2	1	Transfers rotation from gear 2 to plastic shaft	Plastic	Injection Molding	[[Image:]]
024	Plastic Shaft and Oscillation Linkage	1	Interfaces gear 2 Transfers rotation to oscillation linkage	Plastic	Injection Molding	[[Image:]]
025	Oscillation Linkage	1	Transfers rotational motion to angular motion of fan oscillation	??	Cast	[[Image:]]
026	Shaft	1	Transmits motor power to fan and oscillation gearing	Stainless Steel	Extrusion	[[Image:]]
027	Permanent Magnet	1	Uses electromagnetic force to rotate shaft	Ferric Material	Coiled Wire	[[Image:]]
028	Rear Shaft Support and Bearing	1	Supports and allows smooth rotation of shaft	??	Cast	[[Image:]]
029	Front Shaft Support and Bearing	1	Supports and allows smooth rotation of shaft	??	Cast	[[Image:]]
030	AC Motor Block	1	Holds motor coils and electromagnets	Steel	Cast/Rolled	[[Image:]]