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Applied Precision Design, LLC Concept Design Review BioMedical Orbital Mixer. Amir Torkaman Applied Precision Design, LLC 1755 East Bayshore Rd. Suite 9B Redwood City, CA 94063 Phone: (650) 387-7902 Fax: (650) 493-1195 www.AprecisionDesign.com. Typical Design Cycle: Biomedical Orbital Mixer. - PowerPoint PPT Presentation
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Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Applied Precision Design, LLCConcept Design Review
BioMedical Orbital Mixer
Amir Torkaman
Applied Precision Design, LLC1755 East Bayshore Rd. Suite 9B
Redwood City, CA 94063Phone: (650) 387-7902
Fax: (650) 493-1195
www.AprecisionDesign.com
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Typical Design Cycle: Biomedical Orbital Mixer
VIDEO
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Simplified Energy Model: Energy Entering System
Energy Into the System:
Energy Into System = Human Power
Work = Τ∆Θ example: T = 2.25Nm L = 75mm
∆Θ = 30 Turns X 2Π = 188.4 rad W = 423.9 J
Independent of Crank Time or Speed (30 sec)
CONSERVATION OF ENERGY:
Internal energy (stored)
Work Done By System
Energy Into System
Two Modes of Operation:1. Cranking Cycle: Energy In = Energy Stored into System2. Operating Cycle: Energy Stored = Work Done By System
T
L
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Simplified Energy Model: Energy Stored
Energy Stored in the System:
Total Energy = Potential + Kinetic Energy
Kinetic Energy = ½ Iw^2 Potential = m.g.∆h Spring = ½ K ∆Θ^2
m = 5 grams (x4) m = 5 grams (x4) k ~ 23 N-mm / rad d = 50mm g= 9.8 m/sec^2 ∆Θ = turns x 2Π I = 50e-6 Kg/m^2 ∆h = 30mm Spring E = varies with time Kinetic E = 0.88 J Potential E = 0.005 J
CONSERVATION OF ENERGY:
Internal energy
Work Done By System
Energy Into System
T
L
mK W
I
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Simplified Energy Model: Energy Leaving System
Energy Out of the System:
Total Work = Frictional Losses + Drag
Frictional Losses = Σ (ζ.E + μ.N.d.∆Θ) ζ = 3-5 % (gear efficiency)
μ = 0.2 (sliding bearing friction)Total Energy Loss ~ 80 Joules
T
L
mK W
ID (drag)
F (friction)
Drag Force =
C ~ 0.8 A = .0012 m^2 V = 9.4 m/sec F = .05 N (drag force) Drag Energy = 363 Joules
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Power In = Work / Time = 1.90 Watts (after frictional losses)
Drag Power = = 2.02 Watts
Centripetal Acceleration = r.W^2 (120g’s)
Critical Design ParametersV = r.W
r
EXPERIMENTS
Increase Air Resistance(Thru addition of a thin sheet metal foil)Significant reduction in final velocity
Increase Mass 5g 10g(Same max speed / took longer to get to speed
Increase Mass 5g –> 15g(no change in Steady-State conditions) vibration and rattling, more force on bearings
Reduce # of Cartridges Increase of Cartridge Length
m
Critical Design Parameters
g1
Minimize Distance To Center of Mass (r)
Air Drag Coefficient < 0.4
Use Rolling Bearing μ < 0.01
Reduce # of Gears / Belts / & provide Good Alignment
Reduce Moving Mass / Inertia
Improve Gear Efficiency Thru Lubrication ζ < 3%
Drag Power ~ r^3Acceleration ~ r
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Mixer Design
Design Goals Top loading Cartridge top twist in holder Low power loss
Ball bearings Minimize CG dia.
Mixer: 2mm orbital diameter Centrifuge: 1800 RPM
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
COMPARISON CONCEPT 1 - CONCEPT 2
CONCEPT 2: Combined Mixer / Centrifuge
1. + REDUCES OVERALL BOX LENGTH FROM 15.75 TO 14.5
2. - REQUIRES CLUTCH AND BRAKE TO STOP MOTION OF SPINNER WHILE MIXING
3. - INTERFERENCE IF CARTRIDGES ARE NOT REMOVED FROM NON-USED MECANISM
CONCEPT 1: Separate Mechanisms
1. + SEPARATE MECHANISMS SIMPLIFY DRIVE 2. + EASY ACCESS TO CARTRIDGES3. - SEPARATE SHAFT AND SUPPORT4. - TWO ENCLOSURES REQUIRED
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
CONCEPT 1CONCENTRIC MIXER/SPINNER
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
PINS IN SLOTS GUIDED IN SLOTS OF POLYMER BEARING
CONCEPT 1CONCENTRIC MIXER/SPINNER
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
CONCEPT 2SEPARATE MIXER/SPINNER ASSEMBLY
TOP VIEW
15.75”
9”
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
ECCENTRIC DRIVE
ECCENTRIC SHAFT
UPPER BEARINGS
TIMING BELT COGLOWER BEARINGS
Orbital Mixer Design
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Centrifuge Design
Design Goals Top loading Low power loss
Ball bearings Minimize CG dia. Aerodynamic Holders
G1 > 50G G2 ~ 120G G-load axial to cartridge Contain Blood Spill
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
CONCEPTCONCENTRIC MIXER/SPINNER
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
DETAL DESIGN
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
CONCEPT SEPARATE MIXER/SPINNER ASSEMBLY
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Typical Design Cycle: Biomedical Orbital Mixer
VIDEO
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
BACK UP SLIDES
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
CONCEPTSEPARATE MIXER/SPINNER ASSEMBLY
FRONT VIEW
7.75”
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
Centrifuge Design
Calculated Cartridge G’s
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
RIBS ON CARTRAGE PREVENT ROTATION SO THAT CAP CAN BE TWISTED IN PLACE
CARTRAGE RETAINER
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
CONCEPT 1 - ARM WITH PIN IN SLOT PREVENTS ROTATION
PIN IN SLPT
DOES NOT YIELS TRUE ORBITAL MOTION. CARTIRIDGES NEARIST PIN
RESTRICTED IN Y MOVEMENT CARTRIDGES AWAY FROM PIN
EMPHASIXED IN Y MOVEMENT
Y
X
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
CONCEPT 2 - SPRING ROTATION PREVENTER
4X SPRING POST SPRING NOT SHOWN
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
COMPARISON OF MIXER ANTI-ROTATION DEVICES
ARM IN SLOT - DOES NOT YIELD TRUE ORBITAL MOTION.
1. CARTIRIDGES NEARIST PIN RESTRICTED IN Y MOVEMENT2. CARTRIDGES AWAY FROM PIN EMPHASIXED IN Y MOVEMENT
+ Simple Design - FRICTION
SPRING - SPRINGS PRONE TO BREAKAGE - UNKNOWN HARMONICS + LOW FRICTION - NOT GOOD WITH CAP TWIST + Simple Design
SWASH PLATE + ROBUST DESIGN - FRICTION
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
MECHANICAL GOVERNOR WITH SPEED INDICATOR
GOVERNOR
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
MECHANICAL GOVERNOR WITH SPEED INDICATOR
WITHOUT SIGHT
CORRECT SPEED
OVER SPEED
WITH INDICATOR SIGHT
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
ELECTRONIC GOVERNOR
GENERATOR
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
COMPARISON OF GOVERNORS
MECHANICAL GOVERNOR1. - MULTIPLE MOVING PARTS2. - DIFICULT TO CALIBRATE3. - INDICATOR APPROXIMATE4. - DRAG DEPENDENT UPON WIND RESISTANCE
ELECTRICAL GOVERNOR5. +/- POSSIBLY COUPLED WITH RECHARGABLE BATTERY TO INDICATE CRANK
WIND6. + ELECTRIC SPEED INDICATOR7. + GOOD GOVERNOR SPEED CONTROL8. - ADDITION OF MULTIPLE ELECTRICAL COMPONENTS9. - COST OF GENERATOR & CIRCUIT BOARD
NO GOVERNOR – CENTRIFUGE ACTS AS FLYWHEEL10. + ELIMINATES MECHANISN11. - DIFFICULT TO BALANCE/CALIBRATE12. - NO INDICATOR
Applied Precision DesignAmir Torkaman • ENGR10 • Fa13
3 MINUTE ROTATION STOP
PUSH ROD TO RELEASE
SPRING LOADED CATCH LEVER GEAR REDUCTION STACK
INPUT SPROKET