Group16: Assembly Fixture Design and Fabrication for 6 Pole Motor Magnets and their Retaining Parts

Group Members:

Jeffrey Morton

John Pilgrim

Marcus Rothberg

November 12, 2009

Overview Introduction The Problem Product Specification The Design Concepts Design Choice and Walkthrough Experimental Calculations Cost Analysis Conclusion Future Work

Danfoss Turbocor Specializing in commercial

HVACR applications Designer and manufacturer

of world’s first oil-free refrigerant compressors

The largest compressor, that is still in development, is the TT500

The Compressor – TT500 It is currently in its

Beta phase of development

Inside the TT500 is a shaft that powers it

The shaft has a hexagonal center where six rows of magnets will be installed

The Shaft Will have six rows of

magnets secured to it via wedges

Each row of magnets will hold 9 magnets for a total of 54 magnets

The Problem Load and secure magnets and wedges onto the

shaft. Magnets need to be aligned with the poles adjacent Pole orientation alternating from column to column

Causes loading and alignment to be difficult

Magnets The difficulty in

installing the magnets is that the poles of the magnets are aligned

The repelling force of the magnets causes the installation to be difficult

Scope and Customer Needs A new method to install magnets and wedges

onto the shaft Process must be

Safe Ergonomic Accurate Time efficient Non-damaging to parts

Product Specification Budget of $1500 Load and align 9 magnets to each row Installs or allows wedges to be installed in between each row

of magnets A total of 6 rows of magnets Repeatable Completion of assembly within 45 minutes

Design 1: Plunger Fixture

Magnets placed all at once

Holds magnets for wedges and the next column of magnets to go

Initial plunger releases and moves to next column

Loads and installs magnets one at a time.

Cylindrical Sleeve retains magnets on the shaft.

Ferrous bit constrains each magnet as they are lowered onto the shaft.

Wedges may be installed as each row of magnets is installed.

Design 2: Cylinder Sleeve

AligningRings

Retaining Cylinder

FerrousBit

Design 3: Bracket and Rail

Magnets loaded one at a time. Magnets installed in rows of

nine. Magnets are aligned in rail, then

loaded into the bracket and steel fixture.

Steel with magnets is lowered onto shaft and bracket locks into fixture.

Brackets retain magnets on the shaft until wedges can be installed.

AligningRail

Magnet Clamp

Removable Ferrous Bit

Design 4: Trap Door Magnets are loaded Bar clamps and places magnets onto shaft Magnets then secured by rods Bar is removed and process is repeated

Concept Matrix

Specifications:•Precision (40%)•Ease of Use (30%)•Safety (10%)•Durability (10%)•Time (10%)

From Start to Finish Bottom collar halves and aligning cylinder are

placed

From Start to Finish Shaft is placed Top of the cylinder aligns shaft radially Edge of cylinder aligns shaft axially

From Start to Finish Top collar halves are placed

From Start to Finish Alignment cylinder is removed Collar tops are placed to retain collars

From Start to Finish Shaft is placed and located Magnets are to be loaded and placed

From Start to Finish Magnets are loaded one at a time (Part of the fixture base/frame is removed for visual

purposes)

From Start to Finish Magnet row alignment issues Cam device and wall provides solution

From Start to Finish Cam device and wall

From Start to Finish Magnets loaded and aligned with cam Magnets picked up by clamp

From Start to Finish Trap door in loader opens Clamp moves down path to place magnets on shaft

From Start to Finish Retaining rods placed on magnet row

From Start to Finish Shaft is indexed and next row of magnets is to be loaded After all 6 magnet rows are loaded, shaft is removed from

fixture

From Start to Finish Retaining wedges are installed Retaining rods and collars are no longer needed

Completion GREAT SUCCESS!!!

Fixture Exploded View

Analysis Force between two or more magnets Cam displacement polynomials Cam sva graphs Cam profile Time Analysis Material Selection Cost analysis

Magnet Testing The magnets need to be

loaded together. As the magnets get

closer together, the repelling force increases

A force of 26lbs is needed to place magnets together

Loader

Scale

Magnets

Cam Aligner Design

Action Displacement Velocity Acceleration Displacement Polynomial

Rise(0-90deg)

0 0 0

h 0 0

Dwell(90-270 deg)

h 0 0

h 0 0

Fall(270-360deg)

h 0 0

0 0 0

sd ( ) h

vr ( ) h 302

13

603

14

304

15

s.r ( ) h 10

.1

3

15

.1

4

6

.1

5

22

sf ( ) h 1 10

32

2

3

15

32

2

4

6

32

2

5

Cam Aligner SVA Graphs

0 2 4 60.5

0

0.5

1

Displacement

s ( )

0 2 4 62

1

0

1

2

Velocity

v ( )

0 2 4 60.5

0

0.5

1

Displacement

s ( )

0 2 4 63

2

1

0

1

2

3

Acceleration

a ( )

No over shoot in displacement curve.

Smooth velocity curve.

No jumps in acceleration curve.

Cam Profile From displacement curve. Profile equations:

4 2 0 2 4

4

2

0

2

4

Cam Profile

y ( )

cy ( )

x ( ) cx ( )

x ( ) Rb s ( ) sin ( ) v ( ) cos ( )

y ( ) Rb s ( ) cos ( ) v ( ) sin ( )

Center of axle equations:

cx ( ) r sin ( )

cy ( ) r cos ( )

Time Analysis

0 5 10 15 20 25 30 35 40

Ass

embl

y

Time (minutes)

Index and Secure Shaft in Inner Colars

Place and Secure Shaft in LoadingFixture

Load Six Rows of Magnets

Roll Aligning Cams Six Times

Lower and Secure Six Rows of Magnetson Shaft

Remove Shaft From Loading Fixture andInstall Wedges

Preliminary Material Selection Aluminum 6061 for most structural parts

Easy to machine Relatively cheap Noncorrosive Yield strength of 8000psi (55MPa)

Oil impregnated bronze or Teflon for loader lining Low friction Non abrasive

Brass for inner collar Low friction

Cost AnalysisPart Dimension Material Quantity Purchased? Price

Loader H=1”; w=1”; Aluminum Square

Tube 1 no $2.37

Sliding Door H=1”; w=1”; Aluminum Square

Tube 1 no $2.37

Magnet Clamp T=1/2”; L=12”; w=2” Stainless Steel 1 no $38.90

Lever D=1”; L=36” Aluminum 6061 1 no $13.33

Frame T=1/2”; W=4; L=12” Aluminum 6061 4 no $52.36

Collar D=6”; L=6” Brass 1 no $350.29

Hardware NA NA NA no $50.00

Cam D=1”; L=6” Aluminum 2024 1 no $13.34

Cam Plate T=1/4”; L&W=8” Aluminum 2024 1 no $16.38

Cam Aligner Side Plates T=1"; W=3"; L=12" Stainless Steel 1 yes $89.06

Base Plate T=1" ;W=8”; L=8” Aluminum 6061 3 yes $147.90

Other Dimensions Price per hour Quantity Purchased? Price

Machine Work NA $50/hr 10 hrs Donated $500

Total         $776.30

Future Work Finalize design and do detailed drawings with

tolerances. Analyze the four bar lever. Fem Analysis of the magnetic fields and their

resulting forces. Order parts.

Acknowledgements Robert Parsons

Turbocor Machine Shop Supervisor

Clint Bencsik Turbocor Manufacturing Engineer

Alain Pepin Turbocor Mechanical Engineer Design Manager

Jean S. Cote Dr. Daudi R. Waryoba Davey Jones

Reference McMaster-Carr, www.mcmaster.com Norton, Robert L. Design of Machinery 4th

edition, 2008. McGraw Hill. Softwares – ProEngineer Wildfire,

SolidWorks, Mathcad, Microsoft Office

ANY QUESTIONS?

Comments also welcome