DETAILED DESIGN REVIEW

P12026: Transcutaneous Power Transmission

Team MembersNooreldin Amer

Michael CarozzoniWilliam Chan

Naveen GeorgeDevin Prescott

Paul Slagle

Presentation Outline Project Description Review of Customer Needs, Engineering Specifications, and

House of Quality Power Circuit for Motor Armature/Motor Casing CAD Receiver/Generator Casing CAD Generator Selection Power Transmission Test Data Rectifier Circuit Review of Risks System Interface Bill of Materials MSD II Quarter Schedule

Project Description

Team 12026 is currently researching and developing a module for transcutaneous (through the skin) power transmission. Our project involves the transmission of power through a gap using passive magnetic coupling. This unit has potential as a medical device, and is intended as a proof-of-concept for future application in ventricular assist devices (VAD).

Customer NeedsCustomer

Need #Importance Description Comments/Status

CN1 9Transmit power

wirelessly

"Functional prototype paired motor and generator set with passive magnetic coupling." "Delivered system must be “sized” to be able to yield 100 watts at the motor (receiver)."

CN2 9Lasts long and is

reliable"Estimated design life of 99% reliability at 10+ years with 95% confidence."

CN3 9 Safely implantable Bio-compatible and low heat generation

CN4 3 Light "System weight less than 1 pound."

CN5 3 Small"Inner and outer components of the system must each be the size of a hockey puck or smaller."

CN6 3 Contained Shell containing device to prevent unwanted mass or energy transfer

CN7 3 Comfortable Minimize compressive pressure on tissue

Importance: Sample scale (9=must have, 3=nice to have, 1=preference only).

Engineering Specifications

House of Quality

Power Circuit

Component Part

Rectifier 400V 6A Bridge Rectifier

Transformer 120VAC to 12VDC 0.5A

LM7812 12V output

Test Bench

Parallax BASIC Stamp 2 Module

• On-board flash • Vin of 5.5V to 15V• Cheaper than the Arduino Microcontroller• Current members experienced in programming

Sample BASIC Code ' {$STAMP BS2} ' {$PBASIC 2.5}   FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 150

PAUSE 20NEXT   FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 250

PAUSE 20NEXT   FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 350

PAUSE 20NEXT   FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 450

PAUSE 20NEXT   DO PULSOUT 13, 650 %Full speed PAUSE 20 LOOP   END

DK-LM3S-DRV8312After comparing the DRV8312 to the Phoenix Motor Controller from Castle Creations, the DRV8312 has more options and better headroom with supply voltages up to 50V. This also has a higher PWM operating frequency of up to 500 kHz. This is a more robust controller and a better fit.

Case Material

PVC Material Properties

Outside Sub Assembly Preliminary Model

Motor (Blue): EC-i 40 Brushless Outside Shell(Red/Yellow): PVCShaft Mount (Green): AluminumArmature (Orange): PVCMagnets (black/red): NeodymiumMotor Mount (Grey): PVC

Length: 2inOD: 3in

Weight: 0.75lbMax RPM: 9390

Number of Magnets: 6

ANSYS Simulation Armature/Receiver

PVC Material Properties used for ANSYS

Density 1300 kg/m^3

Modulus of Elasticity 2.90E+09 MPa

Poisson Ratio 0.41  

Yield Strength 51.5 MPa

RPM: 20000Material: PVCMax Stress (12 Mag)=8.72 MPa (Pass)Max Stress (6 Mag)= 8.88 Mpa (Pass)

Receiver CAD Model

Height: 35.5 mm [1.4 in]Diameter: 76.2 mm [3 in]Gear Ratio: 3.09:1, 30mm Pitch HelixEpoxy Sealed, USP Class VI

Receiver CAD Model

Receiver CAD Model

Receiver CAD Model

Tooth Profile

Receiver CAD Model

Receiver Sealing

Motor Efficiency

Generator Efficiency

MATLAB Implementation

MATLAB (cont’d)

MATLAB (cont’d)

MATLAB (cont’d)

Generator Selection

Maxon EC22, brushless, 100 Watts, sterilizable

Chosen forOperating point at 8.07 mNm and 45098 rpmLow heat dissipation (0.56 W @155°C)High power output (31 W @155°C)High operating speed (max. 60,000 rpm)High max. ambient and max. permissible

winding temperature (135°C and 155°C, respectively)

Generator Comparison

EC 16 EC 22s

Heat [W] 5.3 4.8

Power [W] 32.9 33.8

Cost [USD] 288 546

Size [mm] 16x56 22x62.7

Max Ambient Temp [°C]

100 135

Operating Torque [mNm]

12.27 14.72

Operating Speed [rpm]

29670 24725

No Load Speed 39200 32700

Magnetic Simulations

Armature/Receiver Testing

Armature/Receiver Testing

Three Phase Rectifier Circuit

Three Phase Rectifier Output Waveform

Output Voltage Regulator

𝑉 𝑜=𝑉 𝑟𝑒𝑓 (1+𝑅2+𝑅3

𝑅1)+𝐼𝑎𝑑𝑗 (𝑅2+𝑅3 )−𝑉 𝑏𝑖𝑎𝑠

Combination of Rectifier and Voltage Regulator

Review of Risks

ID Risk Item Effect Cause

Likelihood

Severity

Importance

Action to Minimize Risk Owner

 

Describe the risk briefly

What is the effect on any or all of the project deliverables if the cause actually happens?

What are the possible cause(s) of this risk?

    L*S What action(s) will you take (and by when) to prevent, reduce the impact of, or transfer the risk of this occurring?

Who is responsible for following through on mitigation?

1High Heat Generation Not meeting specifications,

Low generator efficiency, improper heat dissipation, 3 3 9

Research into generators, dissipating heat properly DP

2High Operating RPM failure Unsafe testing condition Power requirements 2 3 6

Extra layer of safety during testing, gearing DP

3Breakdown Torque/Slippage Lose transmission of power

Large air gap, weak magnet strength, 2 3 6

Ramp-up algorithm, fail-safe mechanism WC

4Low Power Transmission

Not meeting power transmission requirement

Heat specification causing a bottleneck 3 2 6

Research into generators, proper heat dissipation MC

5Low Motor Efficiency

Possible too much heat generation, not meeting other specifications

Lack of research into motors, 2 2 4 Do research regarding motor, NG

6 Large device Not meeting specification,

Trying to meet specification, not enough research 2 2 4

Research components, negotiate with customer, PS

7Failure of parts due to Transience Higher stress Going from 0 to x RPM, 1 1 2

Ramp-up algorithm, factor of safety NA

Likelihood scale Severity scale1 - This cause is unlikely to happen 1 - The impact on the project is very minor. We will still meet deliverables on time and within budget, but it will cause extra work2 - This cause could conceivably happen 2 - The impact on the project is noticeable. We will deliver reduced functionality, go over budget, or fail to meet some of our

Engineering Specifications.3 - This cause is very likely to happen 3 - The impact on the project is severe. We will not be able to deliver, or what we deliver will not meet the customer's needs.

Interface with 12022•Final dimensions of generator and motor from 12026 (housing)•12026 provides 2 interior thermocouples and provides access to them•12026 provides hall effect sensors and provides access to them •12022 provides power to the hall effect sensors and generator side. •12026 provides access to measure on both input and output

Interface with 12022Measurement Unit of Measure 12022 Measurement Range 12026 Operating Range

Input Power to Motor W 0-200 0-50

Output Power from Generator W 0-200 0-35

Thickness of Transmission Material m 0-0.05 0-.025

Contact Force N 0-178 0-112

External Motor Temperature °C 0-100 35-100

Internal Generator Temperature °C 0-100 35-100

External Generator Temperature °C 0-100 35-100

Generator Housing Torque N-m 0-1 0-1

Motor RPM RPM 0-30000 0-15k rpm

Generator RPM RPM 0-50000 0-32k rpm

Bill of MaterialsSubassembly Item Name/Type Owner Amount Units

Cost per indiv. Unit

Net Cost Component Supplier Supplier P/N

Motor Control Phoenix-35 Brushless Motor Control DP 1 ea. $99.95 $99.95 Castle Creations PHX-35 Arrival Date: 2012-03-09Motor Maxon EC-i 40 Brushless PS 1 ea. $323.60 $323.60 Maxon EC-i 40

Motor Casing 3" Dia Motor Casing PVC PS 1.75 inch $1.60 $2.80 McMaster Carr 8745K63 Budget#4-40 3/8" set screw PS 2 ea. $0.15 $0.31 McMaster Carr 92313A017 Unit Cost: $1,613.40#8-32 1/2" set screw PS 6 ea. $0.12 $0.73 McMaster Carr 92313A194 Team Budget: $1,059.952.75" Dia Motor Mount PVC PS 0.75 inch $1.60 $1.20 McMaster Carr 8745K631" Dia Armature Mount Aluminum PS 0.125 inch $1.44 $0.18 McMaster Carr 86985K431#8-32 1/4" cap screw PS 2 inch $0.11 $0.22 McMaster Carr 91251A1903" Dia Motor Lid PVC PS 1 inch $1.60 $1.60 McMaster Carr 8745K63

Generator Casing 3" Dia Generator Lid DP 1 inch $1.60 $1.60 McMaster Carr 8745K633" Dia Generator Casing DP 1.5 inch $1.60 $2.40 McMaster Carr 8745K63Machining Cost DP 1 ea. $200.00 $200.00 First Cut N/A

Generator Maxon EC-16 60W WC 1 ea. $287.71 $287.71 Maxon EC-22Rectifier Power Amplifier NA 5 ea. $5.52 $27.60 Digi-Key LM675T-ND

Voltage Regulator NA 3 ea. $1.40 $4.20 Digi-Key LM340T-15-NDResistor 270k NA 6 ea. $0.36 $2.16 Digi-Key P270kWCT-NDResistor 100k NA 4 ea. $0.36 $1.44 Digi-Key P100KWDKR-NDSchottky Diode NA 16 ea. $0.40 $6.40 Digi-Key 1N5819HW-FDICTCapacitor 1uF NA 6 ea. $0.37 $2.22 Digi-Key PCE3912CT-NDCapacitor 0.22uF NA 4 ea. $0.36 $1.44 Digi-Key PCE3078CT-ND4Potentiometer NA 3 ea. $0.52 $1.56 Digi-Key MCP4013T-502E/CHCT-NDPCB NA 2 ea. $65.00 $130.00 PCB Express Unknown

Receiver Rotor DP 1 inch $1.60 $1.60 McMaster Carr 8745K63M4 Insert, SS DP 10 ea. $1.30 $13.00 Yardley Products Corp 4007Q9-9SSNeodymium Magnets DP 6 ea. $1.01 $6.03 Rochester MangetsRing Gear DP 1 ea. $329.00 $329.00 Arrow Gear 10P16R32Pinion Gear DP 1 ea. Arrow Gear 10P32L16Main Bearing DP 1 ea. $19.60 $19.60 McMaster Carr 2337K561M4 Bolts 8mm DP 10 ea. $2.81 $2.81 McMaster Carr 92855A408Motor Collar DP 1 ea. $3.60 $3.60 McMaster Carr 8992K881Pinion Bearing DP 1 ea. $6.79 $6.79 McMaster Carr 7804K124Motor Clips DP 4 inch $3.35 $3.35 McMaster Carr 9083K361Epoxy DP 5 oz Epotek OG116-31Overmold DP 5 oz Epotek 337

Armature Neodymium Magnets NG 6 ea. $1.01 $6.03 Rochester Mangets UnknownPVC Magnet Housing DP 1 inch $1.60 $1.60 McMaster Carr 8745K63

Power Supply Bridge rectifier NG 1 ea. $0.92 $0.92 Digi-Key SBR05M60BLPDICT-NDCapacitors NTE Electronics NG 5 ea. $1.36 $6.80 Pic Center NEV4700M25IIDRV8312 NG 1 ea. $55.00 $55.00 texas instruments DRV8312DDWRParallax BASIC Stamp 2 Module NG 1 ea. $47.25 $47.25 DIYbin PLX-BS2-ICtransformer NG 1 ea. $10.00 $10.00 Digi-Key 595-1178-NDLM7812 NG 1 ea. $0.69 $0.69 Digi-Key LM7812ACT-ND

Purchasing

Schedule for MSD II